CONTRIBUTORS • Bill Brewer is Susan Stebbing Professor of Philosophy at King's College London. • John Campbell is Willis S. and Marion Slusser Professor of Philosophy at the University of California, Berkeley. • Sam Coleman is Reader in Philosophy at the University of Hertfordshire. • Katalin Farkas is Professor of Philosophy at the Central European University. • Richard Fumerton is Professor of Philosophy at the University of Iowa. • Alex Grzankowski is Lecturer in Philosophy at Birkbeck College, University of London. • Jonathan Knowles is Professor of Philosophy at the Norwegian University of Science & Technology (N.T.N.U). • Joseph Levine is Professor of Philosophy at the University of Massachusetts, Amherst. • M. G. F. Martin is Wilde Professor of Mental Philosophy at the University of Oxford and Mills Adjunct Professor of Philosophy at the University of California, Berkeley. • Anders Nes is Associate Profosser of Philosophy at the Inland Norway University of Applied Sciences • Jessica Pepp is Researcher in Philosophy at Uppsala University. • Thomas Raleigh is Assistant Professor of Philosophy at the United Arab Emirates University. • David Woodruff Smith is Professor of Philosophy at the University of California, Irvine. • Tom Stoneham is Professor of Philosophy at the University of York • Michael Tye is the Dallas TACA Centennial Professor in Liberal Arts at the University of Texas at Austin. 2 [[This is an uncorrected draft. Please do not please do not quote or cite this version!] Introduction: The Recent Renaissance Of Acquaintance Thomas Raleigh, United Arab Emirates University 1. Introduction That there is a distinctively philosophical usage of the term 'acquaintance' is, of course, due primarily to the influence of Bertrand Russell and in particular to the distinction he famously drew between 'knowledge by acquaintance' and 'knowledge by description'. These phrases soon became part of the philosophical lexicon. For example, the Proceedings of the Aristotelian Society twice featured symposia on the question 'Is there knowledge by acquaintance?', first in 19191 and then again in 19492. But then for much of the latter half of the 20th Century, as Russell's influence waned, the notion of acquaintance came to be viewed with grave suspicion by many Anglophone philosophers. This was due in no small part to two hugely influential criticisms of a broadly Russellian picture3: Wittgenstein's (1953) 'private language argument' and Sellars' (1956) attack on the 'Myth of the Given'. However, over the last decade or two, the notion of 'acquaintance' has swung markedly back into fashion in philosophy. The concept has, it seems, become respectable again. This volume gathers together 13 new essays, illustrating the wide range of topics in philosophy of mind, epistemology, philosophy of language and metaphysics, for which the concept of acquaintance is nowadays being utilised4. As ever in philosophy, this term of philosophical art has been used with a variety of different meanings, for various different philosophical projects and purposes, by many different philosophers. But as a first-pass characterisation of acquaintance that I hope most parties could live with: acquaintance is a conscious mental relation that a subject can, supposedly, bear to particular items or features that is, somehow, fundamentally different from thinking a true thought about the item/feature in question. Rather than deploying concepts to form a mental state that is (merely) about something, when we are acquainted with something we are, in some sense, supposed to consciously confront that very thing itself. I suspect that any attempt to further clarify the contrast with conceptual thought, or the precise nature of the 'conscious confrontation', or to state the admissible categories of 1 Featuring G. E. Moore, C. D. Broad, G. Dawes Hicks and Beatrice Edgell. 2 Featuring the great legal philosopher H. L. A. Hart along with G. E. Hughes and J. N Findlay. 3 Though neither Wittgenstein nor Sellars explicitly single out Russell as their target, it is clear that they are both criticizing a broadly Russellian, sense-data picture of experience. 4 See Wishon & Linsky (eds.), 2015 for an excellent recent collection of essays focusing on Russell's theory of knowledge by acquaintance at the time of Problems of Philosophy. 3 items/features that a subject can stand in the acquaintance relation to, is bound to step into contested territory. However, I would venture to suggest that acquaintance could illuminatingly be thought of as a way that the mind can supposedly be 'directed' at an object, which fundamentally contrasts with the notion of 'intentionality' that comes down to us from Brentano. For this latter, 'quasi-relational' notion does not require that the intentional object of a mental state be something that actually exists – e.g. I can think about my Fairy Godmother or about the present King of France – whereas acquaintance is supposed to be a genuine relation, so which could only obtain between a subject and something actual5. The plan for this introductory chapter then will be to briefly consider the Russellian and pre-Russellian history of the concept, to consider a few questions and issues that the notion of acquaintance raises, and finally to survey some of the main philosophical topics for which 'acquaintance' has recently been invoked. 2. Historical background Generations of budding Anglophone philosophers will have gained their first exposure to the philosophical notion of acquaintance from Russell's immensely popular book The Problems of Philosophy (1912). Russell had earlier presented a paper to the Aristotelian society in 1911, also entitled 'Knowledge by Acquaintance & Knowledge by Description', which contains much of the same material that would make up chapter 5 of what he famously called his 'penny dreadful' book. In fact, this distinction between two forms of knowledge already appears at the beginning and end of his famous 1905 paper 'On Denoting'. And a mention of acquaintance occurs even earlier in his Principles of Mathematics (1903). It is plausible that Russell's notion of acquaintance was influenced by his teacher James Ward's notion of 'presentation', which was in turn arguably drawn from Kant's notion of an 'intuition' ('Anschauung')6. But although it was Russell's influence which undoubtedly enshrined the distinction as part of the standard terminology in 'analytic' philosophy, he was not the first Englishlanguage philosopher to use the word 'acquaintance' in this way. Passmore (1957) informs us that John Grote, a moral philosopher and opponent of Utilitarianism, who held the Knightbridge chair in philosophy at Cambridge, distinguishes between 'knowledge of 5 Even this much is controversial – D W Smith (1989, this volume) develops a notion of acquaintance in terms of intentionality, complete with modes of presentation. Mark Johnston (2004) holds we can, in hallucinatory episodes, be acquainted with uninstantiated universals. 6 Ward, who was both a philosopher and a psychologist and advocated a form of panpsychism, held the Chair of Mental Philosophy and Logic at Cambridge when Russell and Moore were students. See Hellie, 2009, for the suggestion that Ward was drawing on Kant. 4 acquaintance' and 'knowledge–about' in his 1865 work Exploratorio Philosophica7. And William James, in his Principles of Psychology, from 1890, likewise uses the term 'acquaintance' when drawing a philosophical distinction between different kinds of knowledge: 'I know the color blue when I see it, and the flavor of a pear when I taste it; I know an inch when I move my finger through it; a second of time, when I feel it pass; an effort of attention when I make it; a difference between two things when I notice it; but about the inner nature of these facts or what makes them what they are, I can say nothing at all. I cannot impart acquaintance with them to any one who has not already made it himself. I cannot describe them, make a blind man guess what blue is like, define to a child a syllogism, or tell a philosopher in just what respect distance is just what it is, and differs from other forms of relation. At most, I can say to my friends, Go to certain places and act in certain ways, and these objects will probably come. (James, 1890, 221) Of course, in many languages other than English, some such distinction is linguistically marked by the existence of two different words – e.g. 'savoir' and 'connaitre' in French, 'Kennen' and 'Wissen' in German, 'scire' and 'noscere' in Latin – a linguistic fact that both Grote and Russell adduced in support of drawing a similar distinction in English. In Germany, at almost the same time as Grote, Helmholtz wrote in his 1868 paper 'The Recent Progress of the Theory of Vision' about a distinction between 'das Kennen' and 'das Wissen' – the former being 'familiarity with phenomena', the latter being "the knowledge of [phenomena] which can be communicated by speech". Unlike Russell, who held Knowledge by Acquaintance to be more fundamental than Knowledge by Description, Helmholtz thought that das Wissen was the more important and fundamental form of knowledge. For though he allowed that das Kennen has 'the highest degree of certainty and precision', he thought, in line with the passage quoted above from James, that it could not be expressed in words, even to ourselves, and was thus unfit to be a basis for science. I cannot say whether William James would have read Grote's work, but he certainly did read and admire Helmholtz. Whatever the precise origins of the philosophical practice of using the English word 'acquaintance' as we do, it seems immensely plausible that something like the same idea or concept of an acquaintance relation has cropped up throughout the history of philosophy under different labels. For example: Sosa (2003) suggests that the notion of 'direct'/'unmediated' cognitive contact that we find in chapter 5 of Problems of Philosophy, 7 John Grote is also credited with coining the term 'relativism'. He is not to be confused with his brother George Grote, also a philosopher, for whom the Grote chair in philosophy and logic at UCL was named. 5 bears a close resemblance to the views of Leibniz, who Russell was reading avidly at the time: "Our direct awareness of our own existence and of our thoughts provides us with the primary truths a posteriori, the primary truths of fact... there is no mediation between the understanding and its objects." (Leibniz, New Essays on Human Understanding, 1765, Book IV ch.9) "We shall say that we have acquaintance with anything of which we are directly aware, without the intermediary of any process of inference or any knowledge of truths." (Russell, 1912, 46) In the same vein, Descartes' foundationalist project would seem to be naturally interpreted as being committed to some sort of especially secure and basic relation that one bears to one's own conscious states – see Richard Fumerton's essay this volume. Brewer (2011) points to Berkeley as an example of a philosopher whose theory of perceptual experience depends on something like a basic notion of conscious acquaintance with minddependent objects – see also Stoneham (2002). McLear (2016) and Gomes (2017) have both recently argued that Kant's theory of perceptual experience is best interpreted in terms of an acquaintance relation with features in the external environment. Woodruff-Smith (1989 and this volume) employs the concept of acquaintance in his interpretation of Husserl – see also Jansen (2014). Gideon Makin (2000) suggests that Russell's acquaintance is really just the very same relation that Frege called 'grasping a sense', though they disagreed over the objects of the relation. No doubt, many other similar precedents of something like the concept of an acquaintance relation could be found throughout the history of philosophy – but that is, I hope, enough history for present purposes. 3. Five Russellian Theses about Acquaintance Russell's distinction was explicitly epistemological, between two kinds of knowledge, but Russell's treatment of the distinction was also intimately bound up with claims both about reference/language and also about the metaphysics of mind/consciousness. Russell, at least around the time of Problems of Philosophy, had a number of commitments that may strike acquaintance theorists nowadays as controversial or just plain wrong: 6 (i) Russell, at the time of 'Knowledge by Acquaintance & Knowledge by Description' (KAKD) and Problems of Philosophy (PP), notoriously held that we are never acquainted with familiar physical items in our shared environment – though it is important to bear in mind that Russell insisted that sense-data are nevertheless mind-independent and ontologically distinct from the subject's conscious awareness of them. Concerning the admissible objects of the acquaintance relation, Russell held that we can only be acquainted with our current sense-data and mental states, plus some past sensedata and past mental states in memory, some universals and possibly also 'the self'. "We have acquaintance in sensation with the data of the outer senses, and in introspection with the data of what may be called the inner sense-thoughts, feelings, desires, etc.; we have acquaintance in memory with things which have been data either of the outer senses or of the inner sense. Further, it is probable, though not certain, that we have acquaintance with Self, as that which is aware of things or has desires towards things. In addition to our acquaintance with particular existing things, we also have acquaintance with what we shall call universals, that is to say, general ideas, such as whiteness, diversity, brotherhood, and so on... It will be seen that among the objects with which we are acquainted are not included physical objects (as opposed to sense-data), nor other people's minds." (Russell, 1912, 51) However, Russell's views on the possible objects of acquaintance had not always been so restrictive. As Peter Hylton points out, in their correspondence from around 1900-1902 both Russell and Moore thought that there was no restriction whatsoever on what we can be acquainted with (see Hylton, 1990, chapter 4). Similarly in the preface to his 1903 Principles of Mathematics, Russell holds that we can be acquainted with abstract logical/mathematical items: "The discussion of indefinable – which forms the chief part of philosophical logic – is the endeavour to see clearly, and to make others see clearly, the entities concerned, in order that the mind may have that kind of acquaintance with them which it has with redness or the taste of a pineapple." (Russell, 1903, xv) Likewise, at the start of Chapter 3, Russell maintains that we can be acquainted with inferential relations: 7 "...it is plain that where we validly infer one proposition from another, we do so in virtue of a relation which holds between the two propositions whether we perceive it or not: the mind, in fact, is as purely receptive in inference as common sense supposes it to be in perception of sensible objects." (Russell, 1903, p33) (ii) Knowledge by Acquaintance is the more fundamental form of knowledge – all Knowledge by Description ultimately depends on Knowledge by Acquaintance. At the start of chapter 5 of problems of philosophy we are told: "All our knowledge, both knowledge of things and knowledge of truths, rests upon acquaintance as its foundation." (Russell, 1912, 48) It seems clear that one might be attracted to the notion of acquaintance and want to assign it some kind of important epistemic role without going so far as to endorse Russell's claim here that all knowledge depends on acquaintance. (iii) We can only understand propositions wholly made up of constituents we are acquainted with. This principle seems to be first stated in print at the end of 'On Denoting': "...in every proposition which we can apprehend (i.e. not only in those whose truth or falsehood we can judge of, but in all that we can think about), all the constituents are really entities with which we have immediate acquaintance." (Russell, 1905, 492) Russell re-asserted this principle in many later works, including both KAKD and PP: "Every proposition which we can understand must be composed wholly of constituents with which we are acquainted." (PP, p58) 'We must attach some meaning to the words we use, if we are to speak significantly and not utter mere noise; and the meaning we attach to our words must be something with which we are acquainted.' (PP58) 'The chief reason for supposing the principle true is that it seems scarcely possible to believe that we can make a judgement or entertain a supposition without knowing what it is that we are judging or supposing about.' (KAKD 206) A re-formulated version of this principle was later influentially championed by Gareth Evans, in his "Varieties of Reference", under the label 'Russell's Principle' 8 "...in order to be thinking about an object or to make a judgement about an object, one must know which object is in question – one must know which object it is that one is thinking about. (I call this principle Russell's Principle...)" (Evans, 1982, 65) (iv) When we are acquainted with a present sense-datum, we are perfectly/completely acquainted with it; there is nothing we are missing, no 'back side' to a sense-datum. "The particular shade of colour that I am seeing may have many things said about it -I may say that it is brown, that it is rather dark, and so on. But such statements, though they make me know truths about the colour, do not make me know the colour itself any better than I did before: so far a concerns knowledge of the colour itself, as opposed to knowledge of truths about it, I know the colour perfectly and completely when I see it, and no further knowledge of it itself is even theoretically possible. Thus the sense-data which make up the appearance of my table are things with which I have acquaintance, things immediately known to me just as they are." (Russell, 1912, 47) A corollary of this thesis is that, for Russell, there is no such thing as different ways or manners of being acquainted with a present sense-datum, there is just the one simple/brute acquaintance relation that can be borne contemporaneously to an item, which reveals it perfectly and entirely as it is in itself. The specific phenomenology of an experience then is determined entirely by the object side of the relation – the subject side cannot also contribute to the phenomenology by being acquainted in this or that specific way or manner. However, as Martin (this volume) points out, Russell did allow for different modes or manners of acquaintance insofar as he allowed that we can also be acquainted with a past-sense-datum – and here the object of acquaintance does not determine the phenomenology of the episode of remembering, rather it is the accompanying imagery which determines the phenomenology. Later, in his Analysis of Mind (1921), Russell came to reject this fourth thesis8, for by that date he treats sense-data as identical with the ultimate physical constituents of reality described by physics and so allowed that sense-data can have further unperceived/unexperienced qualities and characteristics (and indeed can exist unperceived). (v) Despite using the phrases 'Knowledge by Acquaintance', 'Knowledge by Description', Russell thought that acquaintance is not just a means or source for getting knowledge of a distinctive kind. He held that being acquainted with something is already in itself a form of knowledge. To quote again from the passage at the start of chapter 5 of PP: 8 This move towards neutral monism arguably began even earlier, with his 1914 article 'On the Nature of Acquaintance'. 9 "...so far as concerns knowledge of the colour itself, as opposed to knowledge of truths about it, I know the colour perfectly and completely when I see it, and no further knowledge of it itself is even theoretically possible." (Russell, 1912, 47). Likewise in the previous chapter, Russell wrote: 'Acquaintance with objects essentially consists in a relation between the mind and something other than the mind; it is this that constitutes the mind's power of knowing things." (Russell, 1912, 42, bold type added) See Sam Coleman's essay in this volume for contemporary endorsement of this idea that acquaintance is itself a kind of Knowledge. However, I think that the way most theorists use the term 'acquaintance' these days is to denote a relation of direct conscious awareness that allows for a certain kind of knowledge or epistemic relation to an object but which does not in itself count as a state of knowledge. I.e. it is possible to be acquainted with O and yet fail to gain knowledge of any kind of O – one might be distracted or inattentive, one might be deluded or crazy, one could be infected with some reasonable doubt about one's ability to form correct judgements. ****** More generally, I think its fair to say that most recent theorists who have appealed to acquaintance would reject at least one, and quite possibly all five of these Russellian theses. Certainly, none of these five theses are obviously entailed by the core characterisation of acquaintance I gave above in section 1 – viz. a relation of conscious awareness that is fundamentally distinct from thinking a true thought or forming an accurate judgement, in which the mind has some kind of unmediated confrontation with some portion of reality. 4. Five Questions for Acquaintance Theorists In this section, I briefly consider five important questions facing acquaintance theorists. (i) Firstly a methodological question: should we approach the relation of acquaintance primarily as an epistemological topic – i.e. as a relation whose essential nature we define in terms of its being a special source of knowledge or justification? Or should we approach acquaintance primarily as a notion in the metaphysics of mind – i.e. as a relation 10 whose essential nature we define in psychological or phenomenological terms. In other words: should we take the alleged existence of a special kind of epistemic relation as the starting point for our philosophical investigations of acquaintance and only then go on to consider what kind of mental metaphysics or mechanisms that would be required to allow for that epistemic relation? Or do we start from the alleged existence of a special kind of conscious state or relation, posited initially on introspective or phenomenological grounds, and only latterly come to consider what epistemic or referential consequences might flow from such a mental state/relation? Of course, there is no need to treat these two different kinds of approaches to acquaintance as mutually exclusive – after all, it is normal enough in philosophy that we approach an issue or concept from various directions at the same time. Nevertheless, I think it is worthwhile to register that there are these different starting points for thinking about acquaintance and that different acquaintance theorists may have taken one or other route. For example: in his influential work on acquaintance, John Campbell seems to be primarily motivated by epistemological and referential concerns and this has led him to champion a relational model of experience on which the mind is acquainted with external features. In contrast, M. G. F. Martin seems to be motivated primarily by phenomenological considerations to endorse a form of naïve-realism and he has been notably cautious about the epistemological benefits, if any, that might result from adopting this acquaintance-based model. Or to take another example, a number of discussions of acquaintance in the literature on singular thought/reference take their starting point to be the claim that there is some sort of special relation one must have to an item in order to think a singular thought about it (or to understand a singular term which refers to it) – with some theorists arguing for such a requirement and others against it. The precise nature of the mental states or mechanisms required for this relation is then a secondary question. It is not uncommon to read philosophers arguing that there must be some such requirement, but who are happy to leave its exact nature open at least for the time being. For example, Kent Bach writes: 'A de re representation of a material object must be a percept or derive from a percept, either one's own or someone else's.' (Bach, 2010, 55) But how much of an object has to be perceived? is it ok to have only seen a photo of it? What about on TV? What if the object is covered under a thin blanket but you can make out its rough shape and contours? Etc etc. Bach confesses he doesn't really know – his hunch is to be reasonably inclusive, but he draws a line at merely hearing a sound produced by the object. But he's also prepared to allow that the extent of singular thought is much more limited than 11 his intuitions suggest (see Bach 2010, 57-58). Its clear that Bach's real interests here do not lie in the precise nature of the perceptual link that allows for singular thought so much as just establishing that there is some such constraint. (ii) Secondly: is the acquaintance relation non-representational? Or is being acquainted with an object just a distinctive kind – e.g. a non-conceptual or somehow sensory kind – of representational state? In general, those who are writing about acquaintance in the context of the traditional problem of perception have assumed that it is a non-representational relation that stands in opposition to the representational family of theories9. But when it comes to the literature on the hard problem of consciousness this opposition between acquaintance and representation become less clear. On the one hand Levine (2007) and Chalmers (2004, 2007) both hold that we must acknowledge some kind of acquaintance relation to our own phenomenal properties/features, but that this cannot be explained by appeal to a special kind of phenomenal concept – i.e. to a special kind of representational vehicle. On the other hand, Balog (2012) thinks that a special kind of concept – the phenomenal kind, which uses itself to refer to itself – explains what acquaintance is. Being acquainted here then is treated as a special sensory kind of conceptual representation. Paul Churchland (1989), who asserts that "What Mary is missing is some form of 'knowledge by acquaintance'" (Churchland, 1989, 71) provides a neuro-scientific story on which 'acquaintance' is cashed out as a 'distributed representation that is not remotely propositional or discursive'. Likewise, Bigelow & Pargetter (1990, 2006), in providing a physicalist response to Jackson's Mary, appeal to acquaintance, which they understand in terms of a special kind of belief-representation. Earl Conee, in yet another paper arguing that acquaintance holds the key to answering Jackson's Knowledge argument, is explicitly agnostic as to whether acquaintance is representational or not: "Perhaps awareness is experiential pure and unmediated; perhaps awareness of an experienced quality is mediated by some particularly transparent sensory form of representation. What matters for the present account is that experiencing a quality is the most direct way to apprehend the quality. That much seems beyond reasonable doubt." (Conee, 1994, 145) 9 There are by now various hybrid theories in the literature that combine relational and representational elements – e.g. Kennedy (2013), Logue (2014), Nanay (2016), Langsam (2011). But these are hybrid theories precisely insofar as they combine a non-representational relation of acquaintance with the external world together with the notion of representational content. Thus these hybrid theorists are still treating acquaintance as a non-representational relation, even if it is somehow combined into a larger state with a different representational component. See also Bengson et al (2011) for a 'dual component' theory of experience that also combines relational and representational elements. 12 For many epistemologists the point of appealing to an acquaintance relation is to account for non-inferential justification of beliefs, or for a special kind of foundational epistemic security – which in itself does not obviously require one to take a stand on whether the relation essentially involves representational content. A number of recent defenders of traditional foundationalist epistemologies – e.g. Fumerton (1995, this volume), Bonjour (2003) Fales (1996), all maintain that an episode of acquaintance can involve propositional content in the following way10. In order to generate justification for a belief, one needs to be acquainted not only with a fact but also with: (i) a corresponding proposition (about that fact), and, (ii) the relation of correspondence that obtains between the fact and the proposition. However, it is important to distinguish the idea that the object of the acquaintance relation is something representational – such as a thought or propositional content from the idea that the acquaintance relation itself is a form of representation. (iii) Thirdly, what sort of things are we (supposedly) acquainted with? What are the possible objects of acquaintance? We have already briefly discussed Russell's views on the possible objects of acquaintance in section 3, above. It is clear enough that any appeal to (or argument against) some notion of acquaintance needs to consider some of the following sorts of questions: Are we supposed to be acquainted with mind-independent features out in the environment? Or are we only ever acquainted with mental or inner features? Or are we perhaps sometimes acquainted with the outer, sometimes with the inner? Or are we sometimes acquainted with both kinds of features in a single experience? E.g. Wishon (2012) argues that in perception we are simultaneously acquainted with external objects and also with sensory properties of our on experience. Should we treat the objects of acquaintance for each of the sensemodalities along the same lines, or might it be that, say, vision acquaints us with external features whilst, say, taste or smell acquaint us with something inner? Are we acquainted with our own consciousness? Or our own self? E.g. Duncan (2015) argues that we are acquainted with ourselves. Can we be acquainted with acquaintance itself? (Fales (1996) suggests that we can be acquainted with given-ness.) As well as the inner vs outer axis, we can also ask about the metaphysical structure of whatever it is we are acquainted with: Are we acquainted with something (whether inner or outer) like a fact or state of affairs? E.g. Fumerton (1995) and Bonjour (2003) both endorse the idea that we can be acquainted not only with a fact and with a thought but also with the 10	Notice, the idea is that acquaintance can inolve propositional content, not that it always or essentially does so. E.g. Fumerton explicitly allows that one can be acquainted with a fact in a way that does not involve propositional content. Many thanks to an anonymous reviewer for Oxford University Press for helpful discussion on this point. 13 'fit' between the fact and the thought. Or are we acquainted just with the particulars themselves? Or can we also be acquainted with token property instances? Assuming we are somehow or other acquainted with properties, we are obviously bound to ask which properties we can be acquainted with in experience – just as representational theorists are obliged to answer a parallel question as to which properties can be represented in experience. For example: are we only visually acquainted with 2-d shape and colour properties, or can we also be acquainted with other properties – e.g. 3-dimensional shape and depth, perhaps temporal properties, perhaps relations such as identity over time, causation, meaning properties, perhaps the emotions of other people, etc. And if we think the objects of acquaintance are always 'inner', we then face the question of whether these inner items can possess the same properties of shape and colour that we standardly ascribe to environmental items, or whether they instead possess distinct phenomenal properties – shape*, colour*. (iv) Fourthly, another important issue to consider is whether it is possible to stand in multiple different acquaintance relations to the one same object of acquaintance – i.e. can there be different ways or modes or manners of being acquainted with the very same thing? We have already seen Russell in PP insist that when one is acquainted with a sensedatum, one is perfectly acquainted with it – there is, as it were, no back side or hidden aspect to a sense-datum. And it seems that both Moore and Russell around this time held that whenever there is a phenomenological difference between two experiences this is always to be accounted for by a difference in the object side of the relation – see for example Moore's (1903) famous discussion of the apparent diaphaneity of experience. (However, it should be bourn in mind that Moore eventually concluded that one can in fact attend to the act of consciousness itself, as opposed to the object, though it requires a rather special act of attention. It should also be remembered that whilst Russell held there was only one way to be acquainted with a present sense-datum, he did allow that one could also be acquainted with it in a different way, via memory, once the sense-datum was past – see M G F Martin's essay in this volume.) I think this understanding of the acquaintance relation lives on in the literature on consciousness. For example: Chalmers (1996, 2007), Nida-Rumelin (2007), Goff (2011, 2015) all claim that when one is acquainted with a phenomenal property – such as pain or red-looking-ness – one is thereby provided with knowledge of the essence of that property (or at least part of the essence). (Compare Bill Brewer's essay in this volume, in which he defends the thesis of 'revelation'; idea that conscious acquaintance with a property can provide knowledge of the nature of that property.) However, in the literature on perception and naïve-realism we find John Campbell (2002, 2007) arguing that acquaintance is a 3-place relation, whose relata include not just the 14 subject and the object but also a 'viewpoint'. (see also Kennedy (2007)). Similarly Bill Fish (2009) allows that the nature and functioning of the subject's visual system can contribute to the phenomenology of conscious acquaintance. More generally, if an acquaintance theorist holds that we can be acquainted with environmental features, they are going to have to deal with perceptual relativity, the changing appearances of an unchanging environmental object. And so then it seems one has to allow for different ways or manners of being acquainted with the same one item (see Raleigh (forthcoming) for further discussion of this point.) One issue that then arises if one does allow for different manners or modes of acquaintance is the following: how do these modes of acquaintance differ from the orthodox representational notion of a mode of presentation or Fregean sense? You might worry here that once different modes of acquaintance are allowed we begin to lose the contrast between an acquaintance theory and a representational account of experience that treats the alleged contents of experience along Fregean lines. For now on both stories the perceptual experience is directed at an external object or scene, but this external target is presented to the subject via a distinctive mode or manner of presentation. A first thought here might be that representational modes of presentation do not require any actual existing object that the subject is presented with – the object can be merely intentional. Whereas acquaintance is genuine relation that requires both relata to actually exist for the relation to be instantiated. However, if you think, as McDowell (1982) and Evans (1982) long ago urged, that there can be special object-dependent, non-descriptive singular modes of presentation, then this dimension of contrast may be lost. Another obvious way to draw a contrast between the two approaches is to insist that manners/modes of acquaintance are not assessable as true or false, whereas Fregean modes of presentation are. However, not all representational theorists think of the content of experience as having truth conditions – e.g. Tim Crane (2009) insists that experiential content can be accurate/inaccurate but not true/false, since it is not propositional. And likewise, not all naïverealists/acquaintance theorists deny that experiences are assessable as true/false – it is common to read people with naïve-realist sympathies, e.g. Martin (2002, 2004), continuing to use the term 'veridical' as applied to experience itself. A different possible dimension of contrast here is that on the orthodox Fregean account, sense determines reference – that is for any mode of presentation there is a unique (though possibly non-existent) intentional object. So we never find the same mode of presentation presenting different referents on different occasions (though perhaps the same mode of presentation can sometimes succeed in referring and sometimes fail). Whereas an acquaintance theorist can, and I think should, allow that a manner/mode of acquaintance – comprising the various factors both external and internal that contribute to the phenomenology of the experience, e.g. perspective, lighting, condition of one's eyes etc – can 15 be held constant over different occasions and yet acquaint the subject with numerically different items. If I swap one visually indistinguishable item for another and keep the viewing conditions identical, the mode or manner of acquaintance remains the same though the object of acquaintance has changed. Of course this dimension of contrast would also be lost if the representational theorist is prepared to abandon the orthodox Fregean doctrine that sense determines reference. Mark Johnston (2011), whilst arguing in favour of a relational view of perception, briefly discusses the contrast with Fregean senses: 'In an ASE [attentive sensory episode] the target is presented in a certain manner, and the target may or may not conform to its manner of presentation. Hence these manners of presentation are not Fregean senses, which determine something as their referent when and only when the referent satisfies the sense. A target can be presented in an ASE in an illusory fashion and yet the ASE may thereby allow its subject to makes his or her first demonstrative reference to the target, and so have the target as a topic of thought and talk.' (Johnston, 2011, 173) 'The best model of the relation between manner of presentation and target in an ASE is given by 'the theory of appearing' where the manner of presentation just is the target presenting-in-a-certain-manner.' (ibid. 174) In contrast, Levine (2001) assimilates acquaintance to a special kind of mode of presentation – i.e. a phenomenal concept: 'our conception, or mode of presentation of property like redness is substantive and determinate in a way that the modes of presentation of other sorts properties are not. When I think of what it is to be reddish, the reddishness itself is somehow included in the thought; its present to me. This is what I mean by saying it has a 'substantive' mode of presentation. In fact, it seems the right way to look at it is that reddishness itself is serving as its own mode of presentation. By saying that the conception is 'determinate', I mean that reddishness presents itself as a specific quality, identifiable in its own right, not merely by its relation to other qualities. ......the mode of presentation of cathood [in contrast] lacks substance and determinacy.' (Levine, 2001, 8) And in a footnote he adds: 16 'The contrast I'm after between modes of presentation of qualitative properties and other properties (or objects) is perhaps captured in Russell's (1959) distinction between 'knowledge by acquaintance' and 'knowledge by description'. We are acquainted with the contents of experience, but not with anything else.' (ibid.,179 endnote 8) (v) Finally, can acquaintance be further analysed and/or naturalized? It is not uncommon to hear the relation of acquaintance being described as 'brute' or 'simple' – suggesting that in some sense it resists further illuminating analysis. For example, here is Evan Fales: 'the quality of being given is itself given; and moreover, that is itself something simple, not analysable into constituents, in the way in which the content of what is given on a particular occasion might be. As sentient beings, we apprehend, directly and immediately, what it is to be directly and immediately confronted by a perceptual experience... If someone did not already have acquaintance with given-ness, it would be quite futile to instruct him either by employing ostension or by saying such things as that the given is itself given, just as it would be futile to direct the blind person to color sensations by saying that they are visually sensed.' (Fales, 1996, 147-8) Likewise Richard Fumerton writes that Acquaintance: "cannot be informatively subsumed under a genus, and...cannot be analyzed into any less problematic concepts" (Fumerton, 1995, 76) Of course, acquaintance is not meant to be simple or brute in the sense that fundamental particles or forces might be said to be simple or brute. I take it that the idea here is that the state or relation of being consciously acquainted with something cannot be further analysed or explained as being constituted by other, simpler conscious or personal level mental acts or states. And so I assume that neither Fumerton nor Fales mean to be suggesting here that the supposed unanalysability or ineffability of acquaintance shows that the relation could not in fact supervene on purely physical facts. Likewise, naïve-realist acquaintance theorists, will presumably not want to deny that an episode of S being acquainted with O in some way supervenes on or is constituted by some complex extended physical process of interaction, a causal chain running from O to S, reflected light, sub-personal unconscious events in the retina and brain, etc. 17 This might naturally lead one to wonder as to whether some kind of naturalising project could or should be pursued along roughly the same lines as the various attempts to naturalise representational content. I.e. just as many theorists have attempted to state the conditions under which some physical or neural mechanism represents something, in terms that do not take for granted any kind of representational notion – meaning, truth, reference etc, so one might attempt to state the conditions under which a subject is acquainted with something in temrs that do not take for granted anything like consciousness – e.g. attention, or wake-fulness or 'presence to mind' etc. In the context of naïve-realist or relational version of acquaintance, one might look towards Enactive/Embodied/Extended approaches in cognitive science as natural allies when trying to give a naturalistic account of conscious acquaitnanc with one's surroundings. And indeed Alva Noe has described his own Enactivist position as being 'as naïve-realist as one could hope to be' (Noe, 2008, 703). Notice also that even if we accept that the state or relation of being acquainted cannot be analysed into personal level constituents, nor that it can currently be given a reductive, naturlised account, that does not mean that nothing interesting or illuminating can be said about it. Compare: Williamson (2000) famously argued that Knowledge is not analysable and should be taken as an epistemological primitive – but that does not mean that nothing interesting can be said about it, nor that we cannot specify necessary or sufficient conditions for knowledge. Indeed Williamson himself holds that S knows that p iff S's evidence includes the proposition p. And so it might be likewise for acquaintance – even if it is not analysable or reducible into simpler components, we might still be able to say various interesting or illuminating things about it. 5. Some Recent Acquaintance-Based Theorising In this final section, I briefly survey some of the main uses to which the notion of acquaintance has been put in the recent literature – including the essays in the present volume. 5.1 Acquaintance & Phenomenal Properties On Russell's original picture, we are acquainted with sense-data, which were supposed on the one hand to be distinct from familiar objects such as tables and chairs, but on the other hand were also supposed to be mind-independent and ontologically distinct from the subject's conscious awareness of them. If we abandon this Russellian notion of sense-data, we might then think of acquaintance as a conscious relation to familiar objects and features in the external environment, or we might think of acquaintance as a relation that one bears to states or features of one's own mind. A number of philosophers writing on the so-called 'Hard Problem of Consciousness', and in particular in the recent literature on phenomenal 18 Concepts, have had recourse to this latter 'internalist' conception of acquaintance. It is noteworthy that both physicalists and non-physicalists have made appeals to acquaintance in this regard. In the literature initially generated by Frank Jackson's (1982) celebrated "Mary" example, there were some theorists – e.g. Bigelow & Pargetter (1990, 2006), Conee (2004) – who suggested that what Mary gains when she leaves her Black and White environment is Knowledge-by-Acquaintance of a phenomenal quality that she previously knew about only by description. This acquaintance-based response to Jackson's 'Knowledge Argument' can thus be grouped alongside Lewis' (1988) & Nemirov's (1980, 1990) claim that Mary gains a new ability – in both cases the form of the response is to allow that Mary does indeed learn something but to deny that the knowledge in question is propositional knowledge of a fact. And so the physicalist thesis that all facts are physical facts can supposedly be saved. More recently, Michael Tye (2009) also endorsed an acquaintance-based response to the knowledge argument – though in Tye & Grzankowski's contribution to the present volume, they argue that acquaintance is only part of the solution. Tye & Grzankowski hold that when Mary first experiences red she does indeed gain non-propositional knowledge by acquaintance of a simple sensible quality, but they point out that this non-propositional state cannot in itself suffice for Mary's epistemic progress. According to Tye & Grzankowski, knowledge of what it is like to experience red (an instance of knowledge-wh) is propositional knowledge. Tye & Grzankowski go on to argue that although non-propositional acquaintance cannot itself constitute a propositional answer to the question 'what is it like to experience red?', nevertheless acquaintance is vital to understanding Mary's epistemic gain. Acquaintance with the sensible quality in question is that upon which Mary bases her phenomenal knowledge. In the context of the knowledge argument, a propositional answer to 'what is like to experience red?' must be based in one's own acquaintance in order to qualify as an appropriate answer. This position stands in contrast to the phenomenal concept strategy, a strategy that might seek to situate acquaintance in relation to the possession conditions of certain concepts. Since Tye & Grzankowski do not believe that there are any phenomenal concepts, they argue that their "epistemic basing" approach is the preferred way to get Mary's new acquaintance with a color into the story. One obvious worry about the strategy of appealing to acquaintance as a way of defending physicalism, is that this special relation of acquaintance that we can allegedly bear to our own conscious states is, prima facie, just as mysterious and difficult to explain for a physicalist as the 'qualia' of phenomenal red-ness with which we started. E.g. Gertler (1999) argues that it is only property dualists, and not physicalists, who can give a story as to how we can have this special form of access – acquaintance – with qualia. 19 Bigelow & Pargetter's acquaintance-based response to Mary allows that she would come to have a new belief as a result of being acquainted with phenomenal red-ness. By individuating beliefs in this fine-grained way, Bigelow & Pargetter's acquaintance-based theory can be seen as presaging the later literature focusing on the 'phenomenal concept strategy' response to Mary. Phenomenal concepts are meant to be a special way of thinking about a phenomenal property that one can typically only acquire by having a conscious experience featuring that very property – i.e. by being acquainted with the very property that the concept is about. A defender of physicalism can then appeal to this special phenomenal kind of concept in explanation of how Mary can gain new propositional knowledge of the same old physical facts that she already knew couched in terms of neuro-scientific concepts. This strategy relies then on slicing the propositional contents of knowledge-states more finely than facts. A physicalist must insist that phenomenal properties are physical properties and that facts about what it is like to experience these phenomenal properties are just physical facts. The idea then is that Mary, who by hypothesis already knows all the physical facts, can gain a new phenomenal concept when she actually experiences red for the first time – and so she can re-conceptualize a physical fact about the brain using this new phenomenal concept and thus gain new propositional knowledge of the same old fact. Of course, for this appeal to phenomenal concepts to count as a physicalist strategy, one must be able to give a purely physical account of what it is to acquire and deploy a phenomenal concept. That is, one must be able to give an account of what it is to think of a putatively neural property in a special, distinctively sensory way that does not just take for granted the existence of a special phenomenal aspect to the property. Many such theories, which attempt to spell out what is distinctive and special about phenomenal concepts in physicalistically respectable terms, have been offered in the literature. E.g. Lycan (1996), Perry (2001) and Ismael (2007) appeal to the idea that phenomenal concepts are a kind of indexical or demonstrative concept; Loar (1990/1997) and Levin (2007) claim that phenomenal concepts are recognitional concepts; Hawthorne (2002) and Braddon-Mitchell (2003) suggest that phenomenal concepts are conditional concepts. One important suggestion has been that phenomenal concepts are quotational concepts, which use a conscious state or property as part of the phenomenal concept whose referent is that very state or property – just as the device of quotation can embed a word as part of a larger meta-linguistic term that refers to that very word, e.g. "chair" refers to the English word: chair and is also partly constituted by it. Likewise then, the idea is that a token phenomenal concept uses (and is partly constituted by) a token phenomenal property in order to refer to that very property. This kind of approach has been pursued by Papineau (1993, 2002, 2007), Balog (1999, 2012) and Melnyk (2002). Balog in particular has claimed that a quotational account of phenomenal concepts can give a physicalist explanation of our acquaintance with 20 phenomenal properties – i.e. how phenomenal concepts provide/involve a grasp of the phenomenal property's essential phenomenal nature. Sam Coleman's essay in this volume also deploys the notion of quotation in order to give an explanation of our acquaintance with phenomenal properties that is consistent with physicalism. (Though Coleman distinguishes his Quotational Higher-Order Theory of Consciousness from Quotational theories of phenomenal concepts.) In contrast, a number of anti-physicalist theorists have claimed that recognising a relation of conscious acquaintance is mandatory for a good account of consciousness and of our especially intimate cognitive contact with it's manifest phenomenal nature, but that recognising such a relation is a problem for physicalism. Levine (2007) argued that the phenomenal concept strategy as pursued in strictly physicalist terms, fails to account for the special direct acquaintance we have with the phenomenal property. (Levine does not selfidentify as an anti-physicalist, but he does think that the need to account for conscious acquaintance is a serious objection against physicalism.) See White 2007, Chalmers 2007 and Nida-Rumelin (2007) for related criticisms of the phenomenal concept strategy. In his contribution to the present volume, Joseph Levine argues that whilst a non-naturalistic theory of conscious acquaintance is required to explain the especially direct and intimate cognitive relation we have to our own consciousness, such a non-naturalistic theory cannot explain some of the other epistemological and semantic roles of experience that a naturalistic theory of acquaintance is well-placed to explain. When theorising about the metaphysics of consciousness, one might naturally try to start from uncontroversial claims about the manifest phenomenal appearance of experience to the conscious subject's reflective point of view. But what seems uncontroversial and manifest to some philosophers may not seem nearly so obvious to others! For example, H. H. Price (in an oft-quoted passage) wrote: "When I see a tomato there is much that I can doubt. I can doubt whether it is a tomato that I am seeing, and not a cleverly painted piece of wax. I can doubt whether there is any material thing there at all. Perhaps what I took for a tomato was really a reflection; perhaps I am even the victim of some hallucination. One thing however that I cannot doubt: that there exists a red patch of a round and somewhat bulgy shape, standing out from a background of other colour-patches... that something is red and round then and there I cannot doubt...(Price, 1932, p.3) But what seemed indubitable to Price – the existence of some actual red, round particular – has been denied by many adverbial and representational theorists. Likewise, a number of representational theorists have claimed that the representational nature of perceptual 21 experience is obvious or manifest – e.g. Byrne (2001) Siegel (2010) Horgan & Tienson (2002) – though this will of course be disputed by their non-representational oppponents. In his contribution to this volume M. G. F. Martin, considers whether there can be a description of the manifest subjective 'facts of appearance', which remains entirely neutral between the main rival competing metaphysical accounts of what grounds or determines those subjective facts – and in particular which remains neutral between representational vs. nonrepresentational theories. Martin starts his essay by considering a disagreement between different two sense-data theorists – Russell on the one hand, and John Foster on the other – concerning how to explain the phenomenal difference between episodes of sensory perception and episodes of sensory imagination and recollection. Whereas Russell sought to explain both perceptual experiences and conscious imagery in terms of acquaintance with sense-data, Foster proposed a 'two-level' account on which a relation of acquaintance with sense-data – as occurs in perceptual experience – is the more basic explanatory level, and then conscious imagining and remembering are to be explained in terms of a representation of the more basic relational sensory type of episode. An important moral that Martin draws from this debate is that Foster was correct to think that conscious episodes of imagining and remembering are manifestly representational in a way that episodes of perceptual experience are not. And thus, Martin argues, we should reject the idea that there can be description of the subjective facts which remains neutral between representational and non-representational accounts of the metaphysical grounds of those facts. 5.2 Acquaintance & Perception The past couple of decades have witnessed a surge of interest in 'Naïve-Realist' or 'Relational' theories of perceptual experience, according to which we can be consciously acquainted with items and features in the external environment. Theorists who explicitly use the term 'acquaintance' in this Naïve-realist context include: Campbell (2009), Fish (2009), Hellie (2010), Brewer (2011), Soteriou (2013). But even when the term 'acquaintance' is not used – as in, for example, Travis (2004) Putnam (1999), Logue (2012a), Martin (2002, 2004), the relation of direct conscious awareness that is theorised to hold between subject and external object is very plausibly thought of as a variety of acquaintance relation. This surge of interest in Naïve-realism has surely been in large part due to the development of new 'disjunctivist' strategies for responding to the argument from hallucination – a strategy that is standardly credited first to Hinton (1967, 1973) and then developed by Snowden (1980, 1990) and McDowell (1982, 1994) and receives its state of the art defence in the work of M. G. F. Martin (2004, 2006) In its simplest form, the argument from hallucination moves from 2 premises to the conclusion that Naïve-realism is false: 22 (1) Hallucinations are conscious episodes that are not essentially relational. (2) (Common Kind Assumption): Hallucinations and perceptual experiences are the same essential kind of conscious episodes. Therefore: (3) Perceptual experiences are conscious episodes that are not essentially relational. The first premise has generally gone uncontested (though see Raleigh, 2014, Ali 2016; see also Johnston (2004) for the claim that in a hallucination one is consciously related to an uninstantiated universal), as it plausibly seems to simply fall out from the definition of a hallucination. The disjunctivist strategy is to deny (2), the common kind assumption, and to insist instead that hallucinations and perceptions, even when 'subjectively indiscriminable' and/or involving the same neural processes, are fundamentally different kinds of experience. And so a class of subjectively indiscriminable experiences is said to form a (merely) disjunctive kind – e.g. an experience as of a yellow lemon is either a perception of a yellow lemon or a hallucinatory episode that the subject cannot introspectively distinguish from a perception of yellow lemon. But there is, according to disjunctivists, no substantial/fundamental common conscious nature, other than this subjective indiscriminability, that is shared by both disjuncts – though there may be merely neurological similarities. Against disjunctivism, Robinson (1985, 1994) emphasises the possibility that the neural causes/processes involved in both a perception and a subjectively indiscriminable hallucination might be exactly the same. The problem for a disjunctivist then is that once it is admitted that this neural event/process suffices by itself to give rise to the hallucinatory experience and to explain its phenomenology, it seems that in the perceptual case also the presence of this same neural event/process should likewise suffice to give rise to an experience of the same type as in the hallucinatory case. Which would seem to 'screen-off' the alleged acquaintance relation to the external scene from doing explanatory work vis-à-vis the phenomenology of the perceptual experience. In response, Martin (2004, 2006) argues that the disjunctivist should hold that there is nothing more to the conscious phenomenal nature of a causally-matching hallucination than its indiscriminability from some perceptual experience – i.e. it is this negative epistemic condition which explains the phenomenal nature of the hallucination rather than vice-versa. Martin holds that this 'negative epistemic' characterisation of the hallucinatory case avoids the screening-off worry as such a characterisation is essentially parasitic upon the phenomenal nature of the perceptual case – and so the alleged naïve-realist acquaintance 23 relation with external features can still have a constitutive explanatory role vis-à-vis the phenomenology of the perceptual experience11. Just as hallucinations pose a potential threat to the claim that in perceptual experience we can be acquainted with the external environment, so likewise dreams – to the extent that they too are supposed to be episodes with a similarly sensory phenomenal character – might also be thought to potentially undermine 'naïve-realist' positions. Tom Stoneham's essay in this volume considers how a naïve-realist, acquaintance theorist should try to deal with dreams. One possibility would be to adopt a form of disjunctivism – which whilst allowing that dreams have some kind of phenomenal character, would insist that it is of a fundamentally different kind to the phenomenal character of perceptual experience. Stoneham considers this disjunctivist response to be viable but 'requiring considerable confidence with respect to metaphysics' and so 'a comparative weakness of the [naïve-realist] account'. His essay thus explores an alternative non-disjunctive strategy when it comes dreams: deny that dreams have phenomenal character at all. (Compare: Fish 2009 and Logue 2012b both make parallel denials that hallucinations really have genuine sensory phenomenal character.) Whilst this will presumably strike many readers as a counter-intuitive and radical proposal, Stoneham argues that we lack any theory-neutral evidence that dreams really do possess phenomenal character as opposed to a rival view that we confabulate reports and construct false memories of dream phenomenology as a result of cultural influence and social pressures to conform. And so, if one antecedently thought that acquaintance provides the best account of normal perceptual experience, it would be legitimate to prefer the non-phenomenal theory of dreams on the basis that it fits with this best account of perception. As well as the various (disjunctivist or non-disjunctivist) strategies for defending the view against arguments from illusion, hallucination or dreams, there are various positive motivations for the 'naïve-realist' idea that we can be directly acquainted with external features. In sections 5.3 and 5.4 below we will consider some of the epistemic and referential virtues that such a view has been alleged to possess. But another important kind of motivation is phenomenological – i.e. the idea that we need to appeal to acquaintance with external features in order to do justice to the manifest phenomenology of experience. For example, in a series of important and influential papers, M. G. F. Martin (1997, 1998, 2002, 2004, 2006) has maintained that a naïve-realist theory, according to which we can be directly acquainted with familiar mind-independent objects and features in our surroundings, provides the best articulation of how perceptual experience seems to first-personal reflection. Martin (2002) has 11 See Fish (2009) for another presentation of the 'negative epistemic' account of hallucinations. See Sturgeon (1998), Siegel (2004, 2008), Pautz (2011) for criticism of the negative epistemic account. 24 also argued that naïve-realism also provides the best account of the phenomenology of sensory imagining, such as visualising. Another important (and perhaps somewhat unjustly neglected) example of acquaintance-based theorising about perception, in which the motivation for appealing to acquaintance is phenomenological, is D. W. Smith's 1989 book 'The Circle of Acquaintance'. In his contribution to the present volume, Smith endorses the idea that in perception we can be directly acquainted with familiar features in our external environment, but he emphasises that in our everyday actions we can also gain a kind of acquaintance with the objects in our surroundings. Moreover, perception and action are usually 'intertwined' to such an extent that they form a unified sort of experience – 'perception-cum-action'. In unfolding what he takes to be the complex phenomenological and intentional structure of this kind of experience, Smith suggests that acquaintance with the familiar features in our surroundings should be understood in the 'embodied' terms first laid down by Husserl and by MerleauPonty, which have more recently inspired theorists such as Varela, Thompson & Rosch (1991), Gallagher (2006, 2017) or Noe (2004, 2012). This tradition of embodied and enactivist approaches to experience is also an important inspiration for Jonathan Knowles's contribution to this volume. Knowles takes as his point of departure the recent debate between John Campbell and Quassim Cassam (2014) over the relative explanatory merits of an acquaintance-based, 'relational' account of experience vs. a representational account. He argues that Campbell's acquaintance-based view is correct to insist that the phenomenal character of sensory experience is (at least partially) constituted by the external objects and features that we perceive. However, Knowles argues that the relational view does not sufficiently acknowledge the subject's contribution to phenomenal character of experience. He thus advances what he takes to be a superior alternative theory, 'Phenomenological Externalism', according to which the objects and features that we are directly presented with in perceptual experience are part of a 'world-forme' or 'world-for-us'. Knowles's theory is thus appealing to something like the idea of an 'Umwelt' – a term that was due originally to the German biologist Jakob von Uexküll, and which was an important influence on Husserl's notion of a Lifeworld (Lebenswelt). Knowles's essay provides an extended discussion of how such a 'world of experience' relates to the world as described by our best physical sciences. Anders Nes's essay in this volume also engages closely with the work of John Campbell as well as with the work of John McDowell. Whilst McDowell can be classified as a kind of disjunctivist about perceptual experience, insisting as he does that in 'good cases' of normal perceptual experience we are 'open to the world' (McDowell 1994, 111), he does not treat this direct perceptual awareness of our surroundings as a relation of acquaintance. This is because McDowell, following in the footsteps of Sellars and of Kant, insists that perceptual 25 experience itself must already involve the operation of conceptual capacities if it is to be a source of knowledge and justified belief. Whereas acquaintance is supposed precisely to contrast with the sort of thoughts and attitudes that employ concepts. However, Nes suggests that there can be significant convergence between the acquaintance-based, relational position of Campbell and the conceptualist position of McDowell if we consider the crucial role, for Campbell, of conscious attention. Nes argues that attention should be considered a conceptual capacity, in the sense relevant for McDowell's purposes, and thus claims that many of the reasons Campbell provides to favour the relational account can be recast in conceptualistfriendly terms. 5.3 Acquaintance & Reference There is a widely (though not universally) accepted distinction between singular or de re thoughts and descriptive or de dicto thoughts. The core intuition behind this distinction is that one way of forming a thought about a particular object is by thinking of some descriptive condition which that object (uniquely) satisfies. E.g. I may form a thought whose content includes the descriptive condition: the current heaviest sumo wrestler, and by doing so my thought will be about the particular individual (assuming there is one) who in fact uniquely satisfies this condition – in this case, the Mongolian rikishi Ichinojo Takashi. But it seems that at least sometimes one can think about a particular object in a more direct way – that is, not via the satisfaction of some descriptive, conceptual condition but simply as that thing. Granting that such direct, singular reference is sometimes possible, it is often assumed that the item itself would then figure in the propositional content of the thought, in contrast to the general, quantificational structure of a merely descriptive content. There is then a question concerning the conditions under which one can make singular reference to something and here it is often claimed that some kind of acquaintance relation with the item in question is required (at least by somebody, somewhere, at some time); though there is a whole spectrum of views on what counts as acquaintance, and there are also those who deny that acquaintance is a necessary condition on singular reference at all. (Jeshion 2010, Hawthorne & Manley 2012) For example, Imogen Dickie (2010) has defined acquaintance as follows: "A subject, S, is 'acquainted' with an object, o, iff S is in a position to think about o in virtue of a perceptual link with o and without the use of any conceptual or descriptive intermediary." (Dickie, 2010, 213) Dickie then goes on to argue that we can be acquainted with familiar physical objects in our environment, as opposed to the idea that we can only be acquainted with mental items such as 26 'sense-data'. Francois Recanati (2010) takes a slightly different approach, arguing that acquaintance is a not a strictly necessary condition on singular thought, but rather that acquaintance with a specific object is a normative /functional standard or constraint on singular thought – i.e. singular thoughts ought to be tokened on the basis of acquaintance with the referent for this is their proper purpose or functional role. In her contribution to the present volume, Jessica Pepp argues that we should distinguish more carefully between the claim that acquaintance is a necessary condition for a thought to have singular propositional content and the claim that acquaintance is a necessary condition for a thought to be about its object in a direct, 'non-satisfactional' way. Pepp suggests that these two conditions can come apart and so even if it is false that acquaintance is required for singular propositional content, it might yet be true that acquaintance is required in order to think about an item in this special non-satisfactional manner Another, related way in which acquaintance has been thought to be important to reference is to allow for ostensive definitions of concepts/terms and so avoid a regress (or loop) of merely verbal definitions. If we accept that at least some concepts are not to be defined in terms of other concepts, then it seems we will need some other kind of nonconceptual relation to the referent. It is very natural to think that acquaintance with the referent would be ideally suited to play this kind of role – see both Fumerton's and Levine's contributions to this volume for further discussion. This sort of concern about the ultimate basis for our grasp of reference was an important motivation for John Campbell's Reference and Consciousness (2002), a book which played a seminal role in re-establishing the notion of acquaintance as part of the mainstream conversation in analytic philosophy. Campbell famously argued that a nonconceptual, non-representational conscious relation to our surroundings – i.e. acquaintance – is required to ground our knowledge of the reference of our concepts, especially our basic demonstrative concepts. In later work, Campbell (2002a, 2005, 2009, 2011, Campbell & Cassam 2014) has emphasized that conscious acquaintance with the external world is required in order to answer what he calls 'Berkeley's Puzzle': 'Berkeley is trying to respect a principle about the relation between experience and concepts that is both important and difficult to keep in place. This is what I will call the explanatory role of experience. The principle is that concepts of individual physical objects, and concepts of the observable characteristics of such objects, are made available by our experience of the world. It is experience of the world that explains our grasp of these concepts. The puzzle that Berkeley is addressing is that is hard to see how our concepts of mind-independent objects could have been made available by experience of them.' (Campbell, 2002a) 27 Campbell's claim is that experience cannot play the explanatory role we require of it – viz., giving us a conception of a mind-independent world of objects – unless we treat experience as a non-representational relation of acquaintance. In other words acquaintance is supposedly required to explain how it is we can even think about the mind-independent external features of the world, let alone know anything about them. (See Cassam 2011, Campbell & Cassam 2014, Rey 2005 and Jonathan Knowles' essay in this volume for critical responses to Campbell.) Another concern that was already present in Reference and Consciousness was to understand our grasp not only of our own perceptually-based demonstratives, but also other people's perceptual demonstratives. And so we must consider cases of joint attention by two different subjects to the same object. Campbell's suggestion was that the nature of one's experience in such cases of joint attention is fundamentally different from cases of solitary perceptual attention – indeed Campbell claimed we should take a 'relational view' of joint attention: 'Just as the object you see can be a constituent of your experience, so too it can be a constituent of your experience that the other person is, with you, jointly attending to the object." (Campbell, 2002b, 161) In his contribution to the present volume John Campbell revisits his argument for treating experiences of joint attention as 'primitive'. Drawing on empirical work by Michael Tomasello, Campbell argues that the sort of acquaintance with external objects that is required for a grasp of reference, and hence for communication, is grounded in very basic joint-attentional activities that we engage in with our parents or caregivers in early infancy. Campbell thus hopes to effect a rapprochement between the Wittgensteinian idea that shared, public language is explanatorily prior to gaining full-blown propositional attitudes and the core idea of Reference and Consciousness that it is perceptual acquaintance with objects and features in our environment that explains our grasp of reference. 5.4 Acquaintance & Epistemology Russell employed the notion of acquaintance as part of the project of foundationalist epistemology which he saw himself as pursuing. One of the most ancient epistemological dialectics is a concern with a potential regress of justifications – sometimes called 'Agrippa's Trilemma'. Our beliefs stand in inferential relations (or at rather the contents of those beliefs do). When the content of one belief entails the content of another, any justification for the first belief is 'transmitted' to the second. (Likewise when the relation is not full entailment 28 but just probability raising, justification can be partially transmitted or bestowed . . .). But while inferential relations can transmit justification it is not at all obvious, despite what coherentists may claim, how they could create justification in the 1st place. An inferential chain or structure could go around in a circle (or some more complicated web-like structure), it could perhaps extend infinitely, or it can have a terminus – a belief that is not justified via inferential relations. A foundationalist holds that there are such terminal nodes, which are nevertheless justified non-inferentially. Some foundationalists in the past held that these nodes were self-justifying. But the more normal foundational position, these days, is that these terminal nodes are non-inferentially justified by something that is not a belief – viz, an experience. If the experience is to provide a reason for belief that is not itself just a further belief (not just another premise in a potential inference), then the experience must somehow make something available to the subject in a way that is different from just having another belief. And then one way to cash this out is that the subject is consciously acquainted with something – where this episode of acquaintance can provide a reason for believing that p but not by playing the role of a premise in an inference whose conclusion is p. Rather, the experience is held to present or reveal the very things, the truth-makers, that the belief that p is about (see Raleigh 2017 for further discussion of such non-inferential justification). Recent theorists who have explicitly revived this traditional form of acquaintancebased foundationalism include: Moser (1989), Fumerton (1995, 2001), Bonjour (2003), Fales (1996), Hassan (2011, 2013). In a similar vein, acquaintance has been appealed to in epistemological discussions of self-knowledge, where it might be supposed to explain or account for the distinctively secure status of knowledge of our mental states gained via introspection. E.g. Brie Gertler (2011, 2012) has based her account of first person privileged knowledge on the idea that we are acquainted with our own conscious mental states. This revival of traditional, acquaintance-based foundationalism has faced various criticisms. For example: Poston (2010) and Huemer (2007) argue that acquaintance cannot allow for fallibly justified foundational beliefs. (See Fumerton 2010, Hassan 2013 for pro-acquantaince responses.) Whilst Sosa (2003), Poston (2007) and Markie (2009) suggest that 'speckled hen cases'12 pose a problem for an acquaintance-based theories of justification. (See Bonjour 2003, Fumerton 2005 for responses.) In Richard Fumerton's essay for this volume, he continues to pursue his own internalist foundational project in epistemology, a project that he explicitly connects with Descartes' employment of the 'method of doubt' to search for secure foundations for our beliefs. Fumerton holds not only that we can be acquainted with conscious mental states of affairs (facts) and with propositional contents (thoughts) but also with the correspondence 12 The example of a speckled hen is presented by Chisholm (1942), though Chisholm credits the idea to Gilbert Ryle. 29 that can obtain between the fact and the thought such that the former is the truthmaker for the latter. Fumerton claims that when we are acquainted with all three of these factors we would have "strong or ideal" justification for believing the proposition in question. Fumerton argues that such an account can deal with familiar 'speckled hen' type objections by denying that we have genuine direct acquaintance with one or other of these three factors (fact, thought, or the correspondence between them). He also argues that acquaintance can provide a unified account of both empirical and a priori justification. To be clear – one does not have to be an acquaintance theorist in order to accept that there is non-inferential justification or in order to be a foundationalist. For example: Jim Pryor (2000) has influentially argued in favour of the non-inferential justification of beliefs by experience, but he does not make any sort of appeal to acquaintance (though he does think that it is the distinctively 'presentational' phenomenology of perceptual experience which allows it to provide defeasible, non-inferential justification for belief). More generally, one could, prima facie, be a thoroughgoing representational theorist about experience, eschewing all talk of acquaintance, and still maintain that a contentful, representational experience can stand in a justificatory relation to a belief that is not an inferential relation. A different kind of epistemic project for acquaintance, distinct from the foundationalist project sketched above, is to explain how it is possible for us to gain knowledge of the intrinsic, categorical nature of external mind-independent features – as opposed to knowing merely that some or other intrinsic/categorical feature occupies a certain position or role within a relational, theoretical structure. This 'revelatory' function for acquaintance has in recent years been championed both by John Campbell (1993, 2005) and Bill Brewer (2011)13. They have argued that acquaintance with the external world allows us to avoid the sort of epistemic 'Humility' about the intrinsic nature of the external world that Rae Langton (1998) and David Lewis (2009) suggested we are bound to be limited to – a position that is very similar to epistemic structural realism in the philosophy of science (see, for example, Maxwell 1968, Worrall 1989 – though it is arguable that Russell was already endorsing something like structural realism in Problems of Philosophy). In his contribution to the present volume, Bill Brewer argues that only an acquaintance-based account of visual experience can explain such an experience's ability to be a source of knowledge about the intrinsic/categorical nature of mind-independent properties – e.g. a source of knowledge about what it is for something to be round or square, red or blue etc. Brewer argues that two main rival theories, resemblance-based or representational accounts, cannot account for how experience can be a source of such knowledge. And so to the extent that we wish to avoid embracing Humility and accept that experience is indeed a source of such 'revelatory' 13 See also Dasgupta (2015) for another important recent work that appeals to the revelatory function of acquaintance. 30 knowledge about the external world's intrinsic nature, we have reason to embrace an acquaintance-based theory of experience. A rather more specific epistemological topic in which acquaintance has recently figured concerns aesthetic knowledge and judgement. Richard Wollheim (1980) proposed an acquaintance principle according to which it is impossible to gain certain kinds of aesthetic knowledge about O unless one is acquainted with O itself: 'judgments of aesthetic value... must be based on first-hand experience of their objects' (Wollheim , 1980, 233). A number of theorists have argued that Wollheim's formulation is too strong for it would rule out making judgements about a work's aesthetic value based on a reproduction or photograph (see e.g. Livingston 2003, Hopkns 2006). Nevertheless, many philosophers have maintained that Wollheim's acquaintance principle points to something correct about aesthetic judgement and have tried to provide improved reformulations – see e.g. Budd (2003), Todd (2004), Konigsberg (2012), Robson (2013, 2017), Sauchelli (2016) for further discussion. It is commonplace to draw a distinction between knowing-that and knowing-how – i.e. between factual and practical knowledge. Acquaintance raises the prospect that there may be a third important kind of knowledge, which we might call objectual knowledge. We will then naturally wonder whether one or other of these kinds of knowledge reduces to or depends on one of the others. In the case of knowing-that and knowing-how, this question has generated a very large literature (see Stanley & Williamson 2001, Stanley 2010 for recent influential discussion; see Fantl 2009 for a useful survey article). And as mentioned already, in section 3 above, Russell held that knowledge of an object by acquaintance was a fundamentally different kind of knowledge, to knowing a truth about an object – indeed Russell held that knowledge-by-acquaintance was the more fundamental kind. Katalin Farkas, in her contribution to this volume, considers whether objectual knowledge forms a genuine, irreducibly distinct kind of knowledge. Farkas argues that our everyday, natural language talk of 'knowing things' does not express such a distinctive kind of objectual knowledge with its own special, uniform nature. Indeed, Farkas suggests that at least some of our familiar talk of 'knowing things' refers to relations that should not be classified as knowledge at all. However, Farkas concludes that a distinctively philosophical notion of acquaintance with one's own conscious experience might allow us to carve out a narrower but genuinely unified, sui generis category of objectual knowledge. ****** Whilst the foregoing survey of recent acquaintance-based theorising has by no means been exhaustive, I hope that it will, like the essays gathered here, provide a sense of the rich variety of topics for which the notion of acquaintance is currently being employed. 31 References • Ali, R. (2016) 'Does Hallucinating Involve Perceiving?', Philosophical Studies 175 (3): 601-627 • Bach, K. (2010) "Getting a Thing into Thought", in Robin Jeshion (ed.), New Essays on Singular Thought. Oxford University Press. • Balog, K. (1999) 'Conceivability, Possibility, and the Mind-Body Problem', Philosophical Review 108 (4): 497-528 • Balog, K. (2012) 'Acquaintance and the mind-body problem', in Simone Gozzano & Christopher S. 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