teorema Vol. XXXIV/3, 2015, pp. 79-99 ISSN: 0210-1602 [BIBLID 0210-1602 (2015) 34:3; pp. 79-99] 79 The Role of Intuition in Metaphysics M. J. García-Encinas RESUMEN En este artículo voy a estudiar la posibilidad de un tipo de conocimiento a priori que sirve a los intereses de la metafísica, asumiendo que la metafísica entraña la búsqueda de conocimiento modal. El conocimiento necesario, o mejor, modal es a priori; luego el conocimiento metafísico es de igual modo a priori. Defenderé que la intuición es el camino hacia el conocimiento modal en metafísica, insistiendo en que el conocimiento o la posible concepción de verdades conceptuales no lleva al reino modal de la metafísica. Palabras clave: intuición, conocimiento en metafísica, modalidad, a priori. ABSTRACT In this paper I consider the possibility of a kind of a priori cognition that serves the purposes of metaphysics, given that metaphysics involves the search for modal knowledge. Necessary or, better, modal knowledge is a priori; so metaphysical knowledge is likewise a priori. Here I argue that intuition is the route to modal knowledge in metaphysics, and I insist that conceivability or knowledge of conceptual truths does not lead towards the modal realm of metaphysics. KEYWORDS: Intuition, Metaphysical Knowledge, Modality, A Priori. I. A POSTERIORI NECESSARY TRUTHS Before entering into the main discussion of the paper, I need to say a word on the aprioricity of modal metaphysical knowledge. It is usually understood that Kripke dispelled the possible link between modal truths, especially those concerning metaphysics, and a priori truths. He showed how we might come to know a posteriori necessary truths that are essentially metaphysical in character. Thus, modality does not seem to be a privilege reserved for a priori knowledge; it can be empirically known. 80 M. J. García Encinas However, even if there is something true in this train of thought, it also goes beyond a fundamental fact that Kripke also maintained: that a posteriori knowledge of modal truths requires, in all cases, a priori modal knowledge concerning some fundamental category that a posteriori truths exemplify. To know a posteriori that it is necessary that Hesperus is Phosphorus requires the a priori principle that identity is necessary. In all the cases of necessary a posteriori truths considered by Kripke, knowledge of their necessity is a priori: philosophical investigation tells us that they are necessarily true, even when their truth is known a posteriori. A priori philosophical investigation into the nature of mathematics and mathematical reasoning, resolves its necessity – and this is so, irrespective of whether the truth/falsity of particular mathematical statements (say, Fermat's theorem) is known a priori or a posteriori. A priori philosophical investigation into the nature of identity resolves its necessity – and this is so, irrespective of whether the truth/falsity of particular statements of identity (say, that Hesperus is Phosphorus) is known a priori or a posteriori. A priori philosophical investigation into the relation between genus and species resolves its necessity – and this is so, irrespective of whether the truth/falsity of particular statements predicating the belonging of a given species to a genus (say, that cats are demons) is known a priori or a posteriori, and so on.1 Knowledge of truth and modal knowledge must be distinguished, and the latter can only be attained in an a priori manner. The question that guides this paper concerns the kind of a priori philosophical investigation that provides modal/necessary knowledge, such as that advocated in Kripkean texts. In the next sections I argue that knowledge of conceptual truths and conceivability are not wellsuited to this philosophical job. II. ON NECESSITY BY MEANING Many philosophers, especially in the recent past, have actively argued against the possibility of any kind of a priori investigation that provides knowledge in metaphysics. Even though many of their ideas have already been subjected to more in-depth analysis than I offer here, their conceptions of aprioricity will illuminate the discussion. Carnap (1931) famously reasoned that necessary, and thus a priori, truths must be conventional; that is, analytic; that is, about language rather than reality. Metaphysics, a supposedly a priori examination of the structure of the world, is an illusion brought about by careless use of The Role of Intuition in Metaphysics 81 language – to put it charitably. A priori knowledge is knowledge of analytic truths. Why? Because knowledge of the world can be produced only by a posteriori, empirical procedures – this is a defining thesis of positivism. If there were a priori truths or falsities at all, they would not be about the world. Rather they would be mere analytic sentences: sentences devoid of factual content, whose trivial truth/falsity depends on conventional meaning alone. Quine went further than Carnap and attacked not only a priori truths in metaphysics, but also analyticity; and thereby the a priori/a posteriori distinction itself. His celebrated argument in "Two Dogmas" claims that the Frege/Carnap conception of analytic truths as those reducible via definition, or synonymy, to truths of logic, is viciously circular – for definitions are conceptual truths. So, given that a priori knowledge is knowledge of analytic truths, there is no non-circular notion of a priori. The distinction between a priori and a posteriori truths is another dogma of empiricism. It is important, however, to bear in mind that for Quine, just as for Carnap, a priori truths, if there are any, are true by convention. Since Carnap and Quine, considerations concerning metaphysics have evolved. Nowadays, not so many people agree that metaphysics is nonsensical. There is even a rather reputable approach in metaphysics that could be called post-Carnapian metaphysics. Post-Carnapians take the thesis that a priori knowledge is analytic as their starting point and then try to rescue some notion of analyticity from the Quinean critique, in order to defend the possibility of metaphysics. Such philosophers work with a new conception of analyticity, different from that of Carnap and Quine, so that they can save a priori knowledge from the Quinean charge of circularity. Such a new conception of analyticity, in providing new understanding of the a priori, would then constitute the epistemological foundation of modal knowledge in logic and mathematics, as well as in metaphysics. Much of the new metametaphysics project is grounded on these ideas.2 In general, the main argument against "old" analyticity is its conventional character. It seemed obvious to Carnap that matters of meaning are matters regarding generally implicit conventions about our use of words. And this is precisely where Quine attacked analyticity. Quine claimed, first, that conventions of meaning and definitions fall foul of circularity; and, second, that if meaning is not conventional, the idea that the a priori is involved in meaning is hard to swallow. An underlying general point throughout this paper is that Quine's second claim has not been considered sufficiently. Thus, new ways of understanding analytic truths 82 M. J. García Encinas can be found, such that truth by meaning includes non-conventional aspects, or facts about the world. There can be new ways of adding factual material together to arrive at meaning. But then the a priori character of analytic truths, and with it the aprioricity that seems essential for modal knowledge, will be seriously threatened. I claim that metaphysics is not a question of semantics. This reminds me of a joke I once heard from a philosopher of logic: it is obviously false that necessarily all bachelors are unmarried men, as most of them get married. The point is, of course, that one should not confuse use with mention. In the statement that, necessarily, all bachelors are unmarried men, necessity applies to the name of the statement: it does not apply in its content. Thus, even if it is true that, necessarily, all bachelors are unmarried men, nothing in this makes it impossible for bachelors to marry; as they normally do. It could be that synonymy or analyticity are not such obscure phenomena; but Quine is right that there is no way one can get metaphysical, necessary knowledge from knowledge of analytic truths without confounding the predicate of necessity with a statement operator. Necessity from meaning cannot be translated into necessity de re.3 In other words, either analytic truths or truths by meaning are truths by convention, or meaning is understood along factual lines. In the former case, a priori knowledge becomes as problematic as analyticity, and equally devoid of factual/metaphysical content. In the latter, the relevant aspect of meaning that covers factuality is not a priori but a posteriori. Either way, analyticity cannot provide for modal knowledge in metaphysics. Through consideration of a particular approach, I hope to clarify my argument. One well-known proposal that illustrates how to arrive at metaphysical truths from conceptual truths is Jackson's (1998). The proposal essentially consists of defending inferences such as the following. Given the conceptual claim that: Pr. 1 Water = the liquid that we drink, that is in our rivers, etc., [Conceptual claim] and the empirical discovery that: Pr. 2 The liquid that we drink, that is in our rivers, etc. = H2O, [Empirical discovery] we can infer, by the transitivity of '=', the metaphysically necessary claim that: The Role of Intuition in Metaphysics 83 Conc. Water = H2O. The problem is that there seems to be no clear sense in which the necessity of Pr. 1 can help us to know that Conc. is metaphysically necessary. Note that there are four different readings of Pr. 1 (a – d, below), and that Pr. 1 is necessary in only two of them, as I now elucidate. (a) '=' is flanked by a rigid designator, 'water', and a definite description that has a narrow scope: the sentence is a priori and contingent. This would correspond to the sense in which Kripke argued that 'One meter is the length of bar B at t1' is a priori and contingent. That is, there would have been a moment at which somebody said: "Let's call the liquid that we drink, that is in our rivers, etc. 'water'". He would thus know a priori Pr. 1; but then, even if a priori, it is clearly contingent that water is the liquid that we drink, that is in our rivers, etc. When giving it its name, our subject would be pointing to our water stuff, which is not necessarily the liquid that is in our rivers, etc. So, being contingent, Pr. 1 cannot be the route to the metaphysical necessity of Conc. (b) '=' in Pr. 1 is flanked by a rigid designator, 'water', and a definite description that has a narrow scope; but the context is not one in which somebody introduces a rigid designator, but rather a context in which he is merely pointing out true properties of the rigidly designated entity. In this sense, Pr. 1 is a posteriori and contingent. Again, being contingent, it cannot be a route to the metaphysical necessity of Conc. (c) There is also a reading of Pr. 1 where it is necessary and a posteriori. This would be the reading in which the definite description has a wide scope; i.e., Pr. 1 is necessary because necessarily water is that entity which is (contingently) the liquid that we drink, that is in our rivers, etc. However, thus read, Pr. 1 cannot be a route to the metaphysical necessity of Conc., because the information that water is the liquid that we drink, that is in our rivers, etc., is synthetic, contingent and a posteriori. (Thus necessity belongs in the fact that that entity is water; i.e., necessity belongs in the metaphysical relation of identity.) (d) In the most anti-Kripkean reading of all, Pr. 1 could be understood as a conceptual truth, i.e., a pure definition of 'water', as in a dictionary. Pr. 1 would then be necessary and a priori, but useless for any epistemological purpose concerning the nature of our world. I think that this is in fact the reading that Jackson intends; but it is fruitless. For in this 84 M. J. García Encinas sense, Pr. 1 would be equivalent to: the liquid that we drink, that is in our rivers, etc. is the liquid that we drink, that is in our rivers, etc. It would also be equivalent to: water is water. In this sense, and this is again Quine's original point, it cannot demonstrate anything (necessary or not) about the nature of the world: since Pr. 2 is intended to convey empirical (synthetic) knowledge, it is not valid to then substitute into it the definition that this reading of Pr. 1 provides us with; i.e., the substitution does not yield the empirical (synthetic) knowledge that Pr. 2 is intended to convey. The problem in a nutshell is then that there is no clear sense in which the alleged conceptual necessity of the claim that water = the liquid that we drink, that is in our rivers, etc., can help us to determine the ontological necessity of water being H2O. There is yet another reason to deny the notion that conceptual truths play an essential or indispensable role in metaphysical knowledge: natural language is not our only, nor even our best, way to grasp metaphysical ideas. There are other languages that perhaps, or for certain people, are better ways of expressing and understanding metaphysical facts. For example, the sculptor Oteiza can show the metaphysical nature of space as emptiness, or as a pure relation created by matter, as well as any philosopher of physics who denies that space is a Cartesian receptacle can. Kripke insisted that the thesis that identical objects are necessarily identical is one of the "(self-evident) theses of philosophical logic independent of natural language." [(1980), p. 4; my italics]. The thesis that identity is necessary, where identity is a relation of objects, is not analytic in character, nor does it depend on natural language. In general, Jackson's scheme should be replaced by something like the following: (I) Any entity is necessarily identical to itself. [a priori] (i) If water is identical to H2O, then water is necessarily H2O. [a priori] (ii) Water is H2O. [a posteriori] So, (iii) Water is necessarily H2O. [a posteriori] The Role of Intuition in Metaphysics 85 Identity is a necessary relation. So any true identity statement, such as "water is H2O", is necessarily true. But it is not analytically or conceptually true that identity is a necessary relation. It is evident in itself that no entity can be another. However, the reason for and understanding of this self-evident thesis of philosophical logic that is independent of natural language are still to be elucidated. III. METAPHYSICAL TRUTHS Metaphysics seems to be concerned with knowledge of highly abstract philosophical categories. I have more or less restricted the discussion to identity up until now, but there are many others: causality, time, space, existence, the self, natural law, substance, beauty, and so on. So metaphysics is not concerned with terms such as 'water', 'energy', 'temperature', 'tigers', 'ships', and so on – except in the trivial sense that they are examples or case studies of the categories themselves. To mention again the most hackneyed case, metaphysical considerations concerning 'water' are metaphysical considerations of identity. And when it comes to the study of the modality they convey, the study of categories involves abstraction from their empirical content and exemplification. Categories govern all things or facts in the world, and over all possible things and possible facts. Thus, the principles that govern categories seem to be that kind of truths, or apparent truths, that present themselves to us, not just as true, but also as involving some sort of modality: it is not that there is a sufficient reason for everything, but that there must be one; not only that entities exist in the world, but that their existence is contingent; that causation is a necessary relation; that every temporal thing must exist at some present; that nothing can be bad but beautiful; and so on. Metaphysics searches for modal truths that are ultimate principles of reality. However, modal knowledge, in metaphysics as much as in any other discipline which aspires to attaining it, is a priori knowledge. Even if particular instantiations of modal truths can be known a posteriori, they rest upon a priori modal truths. The usual reason behind the idea that modal knowledge is a priori is that empirical experience is always subject to error: empirical experience can deceive us, so it cannot be the source of necessary knowledge. I think this reason is highly misleading. Error is part of human nature, just the same. 86 M. J. García Encinas The true reason why necessity must be known a priori is that no instance of empirical knowledge can provide for the modo of reality. Empirical generality cannot provide necessity: no matter how many crows you count, although you may come to know empirically their actual number, you can never how many there must be. Neither can any empirical fact provide for contingency: you count twenty crows, but neither the result, nor your counting itself, will tell you that there could have been fewer, or more, or none. Empirical knowledge provides you with facts; but it cannot tell you whether those facts are contingent or not. So, if some facts are also modal in character, if modal knowledge is possible at all, knowledge of their modo must be a priori. The problem of course is how to determine the sort of a priori access that is required for knowledge of modality. IV. ON CONCEIVABILITY The popular view sees conceivability as our a priori epistemological access to modality. It holds that whatever is conceivable – and it is presupposed that nothing that is logically impossible is conceivable – is possible. Thus, necessity resides where its contradictory cannot be conceived. But what is it to conceive? To think? To understand? To imagine? If we want to distinguish between imagination and understanding, for instance in Cartesian terms of images versus concepts/ideas, then the notion that conceivability is our guide to possibility means that our understanding, but not our imagination, is what properly conceives. For there are too many ideas whose images the imagination cannot form, but that are clearly possible. We can imagine a figure of ten or perhaps twenty sides and understand the corresponding ideas; but even if we possess and understand the concept, we cannot imagine a figure of infinite sides. The idea of being infinite is perfectly coherent, and it is even a possibility that our universe is infinite in time or space; but we cannot form this possibility in our imagination. There are possibilities that our imagination cannot imagine. So our understanding, but not our imagination, is the proper guide to possibility. However, it is not easy to make sense of the distinction between imagination and understanding in terms of images versus concepts. When good poetry makes a stronger impression on us than painting, as it usually does, do the words impress our imagination, or our understanding? Is this strong impression caused by concepts, or by the images that the words on The Role of Intuition in Metaphysics 87 the paper signify or provoke in our minds? Just by way of an example, consider the description of Satan given by Milton: ... His form had yet not lost All her original brightness, nor appeared Less than archangel ruined, and th'excess Of glory obscured: as when the sun new risen Looks through the horizontal misty air Shorn of his beams; or from behind the moon In dim eclipse disastrous twilight sheds On half the nations, and with fear of change Perplexes monarchs, ... Can you tell the difference between imagining and conceptually conceiving Satan? Powerful and confused images or ideas absorb the mind when we read or hear this passage and experience the sinister nature it conjures up. Our minds are clearly moved, but by blurred images? By obscure concepts? I think these are the wrong questions. The question concerning our knowledge of metaphysical necessity cannot be resolved by deciding the medium – images, concepts, propositions – we use for metaphysical thinking, because the old formula (whatever is conceivable is possible) is simply false. Whether it is in the form of images, concepts, propositions, or whatever, we clearly can conceive what is impossible. We can conceive that water is not H2O; we can conceive that we can demonstrate (Kant did) that the universe had a beginning and that it had no beginning, that π is not 3.1416, and so on. Conceivability, irrespective of the medium that is needed for conceiving, is just not the guide to modal knowledge. Many still insist that conceivability leads to possibility. Situations of modal error, they say, are situations where the link between conceivability and possibility seems to break down. It seems to break down, but it does not. For when we are supposedly guilty of modal error, in fact we are mistaking some different imaginary/conceptual/ propositional situation, a fake, for the real one. When we make a modal mistake, we conceive a different situation from the one that the evaluated sentence seems to represent. But conceivability and possibility still go hand in hand: there is some privileged proposition that shows the appropriate a priori truth that is "always" necessarily true. Chalmers (2004) explains the conceivable situation that water is XYZ in the following way. There are epistemically possible worlds where 88 M. J. García Encinas water, i.e., the liquid we drink to survive, is XYZ. These worlds are metaphysically impossible because we, in our world, have discovered that water is H2O. But 'water' picks out other entities (such as XYZ) at other possible worlds. If we keep the referent of 'water' fixed in our world, worlds where water is not H2O are counterfactually impossible. But they are still possible, for we could have discovered that the liquid we drink to survive, etc. had a different composition. Our world could then have been a world where water is XYZ. There is no contradiction in this. Our mind misleads us, but not because we imagine or conceive the impossible. Our mind misleads us because what we conceive and what is the case are different things. When we conceive that water is not H2O, what we conceive is the different, but similar enough, situation in which a certain liquid, which has the usual macroscopic properties that water has, is XYZ. Equally, when we conceive that the Sun is a god, what we conceive is the different, but similar enough, situation in which the celestial body that is big and yellow and was believed to rotate around the Earth is a deity. We conceive through true properties, or descriptions of the entity in question, but somehow we lose sight of the true referent of these descriptions: we are not really thinking of the entity that is our water, the Sun, etc., but of some other entity that could have had many of the contingent but salient properties or our water, our Sun, and so on. If this view is correct, to conceive that it could have been the case that the Sun is a god, is to conceive that some sun-like body, but not the Sun, is a deity. I think this is simply wrong. Metaphysics is not primarily concerned with what sentences would, or could, say in different situations, or under different uses of language; but with the ontological commitments of true sentences. For Chalmers, when we conceive the negation of a true, necessary statement, such a conception does not convey to us that the corresponding fact is not the case; rather, the statement acquires a different meaning and some fake fact takes the place of the original one. This is a high price indeed to pay for hanging on to the conceivability-entails-possibility thesis. To be sure, it is possible that 'water' (the term or its intension) is used to refer to some other stuff. It is also possible that our cognitive faculties could have been different or inexistent. It is possible that most of the properties that water has, being contingent, could have belonged to some other stuff that is not water. These are possible, and conceivable, situations; but these possibilities are not what we conceive when we conceive that water is not H2O. The Role of Intuition in Metaphysics 89 Metaphysical impossibilities are conceivable. I can imagine that the Sun is a god. I can conceive that cats are demons and people are Martians in disguise. I can conceive that an omnipotent God can create a stone that She cannot move. I can dream that I am my beautiful sister. I can imagine, like Kripke, that the ducks in Central Park are demons. I can suppose that Achilles actually walked, in a finite time, an infinite number of steps before he caught up with the tortoise. I can conceive these situations – as others can – but, of course, some of them at least are metaphysically impossible. Imagination or conceivability is neither proof of possibility nor a limit to necessity. But why? This is my guess: modality, including metaphysical modality, is no content of thought, but its condition. Modality is a priori because it belongs to the framework of thought and experience, as much as it belongs to the framework and conditions of reality. Necessity, or possibility, cannot be revealed through any kind of empirical research into the world, because it belongs in the ultimate categories that are the very conditions for experience, and language, and thinking. V. THE REALM OF PURE REASON So where does the a priori guide to metaphysical principles reside? If modality is not within the scope of experience, of imagination, if it is not the content of thought or meaning, if it belongs to the framework and condition of experience itself, then metaphysical objects and principles must be intuitions, or intuited. So there is an intimate, immediate, awareness of modality. Intuitions are insights that guide the activity of our imagination, our senses and, in general, our knowledge and thinking. This intrusion into the activity of thought and language is not propositional or conceptual– even though, after being noticed or acknowledged, it could become part of propositional content. Kant wrote, on mathematical knowledge: A new light flashed upon the mind of the first man who demonstrated the properties of the isosceles triangle. The true method, so he found, was not to inspect what he discerned either in the figure, or in the bare concept of it, and from this, as it were, to read off its properties; but to bring out what was necessarily implied in the concepts that he had himself formed a priori [Critique of Pure Reason Bxii]. 90 M. J. García Encinas This new light that flashed upon the mind of, perhaps, Thales, this kind of knowledge, is immediate and, like empirical knowledge, it is a kind of experience. Intuition is Thales' experience that the content of his mathematical finding could not be otherwise, and the experience that everybody else should experience this feeling of necessity when entertaining the same content of thought. In contrast to imagination, perception or propositional thought, intuition does not "produce" representations, images, concepts or thoughts. To intuit is not to imagine something, nor to conceive a situation, nor to know empirically by sense or introspection. Intuition of modality is a feeling; and what is felt is not a proposition but a modo. When intuited, necessity is not inferred or deduced, but experienced. And the subject who experiences it experiences that the thought is necessary, and that everybody else – even Descartes' Polyandro – must have the same feeling, the same intellectual vision when entertaining the same thought. It is not an experience reserved for special people: no rare power of the understanding, but a common function of reason on a par with, but not identifiable with, common sense. In the Regulae, Descartes said that in mathematical reasoning we find reason at its best: beginning with self-evident data, reason reaches conclusions with certainty following a deductive process of self-evident steps from data to data. Thus, deduction and intuition are both powers of reason. Deduction is the active power to move by an uninterrupted sequence of self-evident steps, from data to their consequents. Intuition is the passive power of apprehending self-evident data. Philosophical intuition is to see, for instance, that self-consciousness, even by momentary doubt, necessarily implies existence. It is to see that self-identity is necessary; that necessarily Pa x Px; that every particular effect necessitates its cause; that existence is contingent; that torture should not happen; that time needs change; and so on. These pure apprehensions of reason primarily concern fundamental philosophical categories of existence, causation, time, the person, the good, etc.4, 5. Categories are not primarily concepts. Self-identity, for instance, is a metaphysical relation, or perhaps a property. It is a metaphysical category that belongs in reality and into which the natural light of reason can penetrate and apprehend. Thus, intuition, at least when doing its job for metaphysics, deals directly with its abstract "objects" or philosophical categories and perceives their nature. The Role of Intuition in Metaphysics 91 You cannot deny an intuition, which is an act of reason, even if you can deny its propositional content. So, to deny an intuition is not to have a feeling of counterintuitiveness [contra Williamson (2007), pp. 218-219]; intuitions are only elliptically deniable. You can deny that identity is necessary, or the rule of modus ponens, for instance; but when doing so, your reason actively denies a proposition and it does so through much effort. Certainly, much philosophical work is achieved by actively denying or confronting intuitions; so much that you could say that philosophy is often a "mere" purging of intuitions. BonJour has also argued that a priori metaphysical knowledge consists of direct or immediate insight into modality. He claims that "a priori justification occurs when the mind directly or intuitively sees or grasps or apprehends ... a necessary fact about the nature or structure of reality." [BonJour (1998), pp. 15-6]. My rephrasing of this: a priori metaphysical knowledge is rational insight into the categories and deep modal structures in the world. Many of BonJour's claims, including the fallibility of intuition, are in the spirit of what I am proposing here. VI. ON THE FALLIBILITY OF INTUITION There is a crucial point that I have not mentioned yet: the idea that a priori knowledge is subject to correction. It is almost universally assumed that a priori knowledge cannot be mistaken; after all, it is the source of necessary truths. This assumption explains why mathematical and logical reasoning and principles are immediately considered as possible instances of a priori knowledge. However, I think there is a dangerous misunderstanding here. The realm of the a priori is the realm of modality. But let us focus here on necessary truths, as it is their necessity that grounds the idea that a priori knowledge is infallible. I claim that necessary truths, or the necessary truths upon which other a posteriori necessary truths depend, can only be reached a priori. But a priori routes are not routes of certainty. To know a priori is to know by intuition: it is to experience that a thought cannot but be the case, and that everybody who is in the same state of thought must have the same experience of necessity. But, of course, the experience could be felt when the propositional content of the thought is not necessary, or even true: intuition can go wrong. We have the conviction that identity is necessary. We strongly feel the need for a time before today. We feel that tigers are necessarily ani92 M. J. García Encinas mals; that 1+1 is necessarily 2. But we could be wrong. Perhaps the distinction between genus and species does not belong in the world; perhaps only the present is real; perhaps there are no entities in the world; perhaps we have to change our arithmetic. These ideas are farfetched in the extreme (that is why we experience them as necessarily false), but they could be right. New data, the development of new scientific theories, the discovery of inconsistency with other a priori principles and, in the end, the development of philosophy, could make us understand that their necessity was an illusion. A priori knowledge of necessity is not necessary knowledge; and knowledge is not necessary because it is a priori known. To know a priori is to have the intuition that something is so and so of necessity; but our intuition can fail just as any other of our faculties can. Tradition disagrees, and the idea that pure reason cannot fail to think properly is old enough. Even the sceptic refrains from questioning this capability of pure reason. And I agree that there is something in this: one cannot doubt everything, for even doubt must be coherent. You can doubt tertio excluso, the rule of existential generalization, modus ponens, etc., but only insofar as you count on something which you do not doubt. Otherwise, you will simply be unable to make a single claim. This, however, is all there is to the infallibility of reason, also in its passive power to intuit. That you cannot doubt everything does not imply that pure reason is infallible. Descartes was well aware of the impossibility of doubting everything. However, he also believed that intuition cannot go wrong. Descartes understood that he could doubt mostly everything; he thought he could doubt any information provided through his senses, up to the point of being uncertain as to whether he was dreaming or not. He even seemed to consider the possibility of a malignant demon that deceived him in his mathematical thinking, in the First Meditation, and again in the Third: Indeed, if I have judged since that these things [any and every simple and easy matter in arithmetic and geometry, such as, for example, that two and three make five, and other similar matters] can be doubted, it has been for no other reason than because it occurred to me that a God might perhaps have given me a nature such that I might make mistakes even concerning the things which seem the most obvious to me. (...) And on the other hand, every time I turn towards things which I think I conceive clearly, I am so persuaded of their truth that I spontaneously declare: let him deceive The Role of Intuition in Metaphysics 93 me who may, but he shall never be able to cause me to be nothing, so long as I think that I am something." [Third Meditation, pp. 114-5.] Did Descartes consider the possibility of being deceived in all his "certainties," including all his intuitions? No. There was the indubitable intuition that he exists if he can doubt everything else. Had he doubted all intuitions, he could not have had any first certainty: he would have never written that, even if deceiving him, the demon could not have stopped him knowing that he existed. He could never have stated the Cogito. So Descartes is implicitly saying here that intuition, the natural light of reason, is the most powerful tool that people possess in their search for knowledge: more powerful than deduction;6 more powerful even than the principle of non-contradiction [Descartes, La recherche, p. 91]. For even the principle of non-contradiction is known to be certain by the natural light of reason.7 So the malignant demon did not deceive Descartes in all his intuitions. As is well known, Descartes concluded from the experience of and reflection on the Cogito that intuition, the light of reason, was the light of certainty. But this was his mistake. For even if there must be some certain knowledge without which one cannot even begin to think, and even if intuition is our best tool to attain this foundational knowledge, nothing here guarantees that intuition is infallible. If nothing else does, the history of philosophy, of logic and of mathematics demonstrates how the very best of minds can be mistaken in the most certainly felt intuitions. VII. WIT There is a repeatedly alluded to difficulty concerning intuition in metaphysics: the mystery that seemingly surrounds a kind of knowledge that, being about our world, is at the same time independent of empirical experience. As Devitt (2005) wonders, what sort of non-empirical link to reality could support insights into its necessary character? I do not think that this activity is more mysterious than many other common activities of human beings, and even of other animals. We hear bells, we love and hate people, we know that yesterday we ate grapes for lunch; and we are conscious of doing all these things. Are these experiences, feelings, and actions of ours really less mysterious than intuition? 94 M. J. García Encinas Throughout this paper I have claimed that modal metaphysical knowledge is, ultimately, a priori. A posteriori knowledge of necessary or contingent facts, such as that Hesperus is Phosphorus, that Sandy must not hurt Pandy, or that Rufo is a contingent being, rests on a sort of a priori knowledge that finally concerns old metaphysical categories, such as identity, the good, the person, existence, etc., and relations between them. Modal metaphysical knowledge is a priori and concerned with highly abstract philosophical categories, because there is no way in which empirical experience of particular entities, such as Hesperus, or particular facts, such as there is cat, can provide for their modal properties. You cannot know that cats cannot be demons by observing particular cats; you could at most know that no cat is a demon – although of course, empirical experience alone does not allow you to state this negative or universal fact either. Modality is a feature in the world; but we are not aware of it by observing nude particulars. You can be empirically aware of the fact that you are writing on a table, but no empirical experience informs you of the fact that you could be writing in some other place, or not writing. There can be no empirical knowledge of the contingency of the fact that you are writing. You can also learn necessary truths by experience or a posteriori, as when a child learns multiplication tables or the Ten Commandments by memory; but then the child is not learning that these truths are necessary. Modal understanding can only be attained by natural reason. I have also insisted that the job of reason, when reason is applied to knowledge of categories, is not merely conceptual. It is not by analysing the concept of water, or demon, that reason understands the modal features of water or demons; but analysing the category–concept of identity, or species, or existence does not take reason much further. In the first pages of this paper I tried to stress Quine's important point that there is no way you can get metaphysical modal knowledge from knowledge of conceptual truths without confounding modal predicates with statement operators. Then I tried to show that imagination and conceivability, at least as usually understood, cannot lead to modal knowledge either. In general, analyticity and the activity of imagination, traditionally the two main empiricist routes chosen to account for modality, are unsatisfactory. I then proposed intuition as the "passive" activity of reason which grasps the modal character of reality. Returning for a moment to imagination and conceivability, it seems to me that the idolatry of these activities of the mind by the empiricists of the seventieth century is responsible of their overuse. They were beThe Role of Intuition in Metaphysics 95 lieved to be capable of finding new relations among ideas, revealing new ideas from old ideas and impressions, explaining sympathy and moral attitudes, and accounting for artistic creativity. Although I cannot go into this point in depth here, this abuse of imagination was as harmful for metaphysics as it was for ethics or, especially, aesthetics; it provoked an almost unbridgeable breach between reason and the world. However, we face up to the world by reasoning as much as by sense experiences. And when the former occurs, intuition is one of our preferred capacities that we bring to work. Given his intellectual position, unaware of the dominant role that imagination was playing in philosophy and art, the Spanish monk Baltasar Gracián proposed an a priori activity of the mind which, being rational but not logical, was the source and explanation of human creativity. He called it 'wit'. I want to claim that the capacity of intuition is none other than this wit of Gracián's. Gracián claimed that when wit joins normal thinking, including logical activity, the result is vigorous understanding. Wit is creativity; a capacity that allows the mind to reach its highest achievements. It is the stimulus of thought, so it does not belong in imagination; but it is the aid of understanding, and the stimulus of reason and conceptual thinking. Wit is the light that comes to the mind when it sees something it had not seen before, when it grasps a thought or a fact. It is the foremost intellectual quality of the human being. It is the aid of the genius. And even if there are no rules for wit – if there were, it would not be wit, but active reasoning and deduction – it can be recognized, and educated, and improved through practice. Thus, even if it is not a necessary condition for wit, competence in a given field, be it mathematics, logic, art, or philosophy, will most certainly improve the capacity for rational insight concerning matters in that field. We are all familiar with this capacity. Think of any idea that you wish someone to believe. You will present to them with all kind of reasons, arguments and explanations so that they can understand and accept your idea. But, as necessary or useful as all of them could be for your purpose, no kind of reason that you might come up with, no reasoning whatsoever, logical, conceptual, by example, by comparison, citing facts, etc. will constitute the other person's understanding: the light that will illuminate their mind when they finally see and accept what you mean. That is rational intuition.8 Wit, rational insight, is the capacity to see new "conceptual" relations, to grasp and intellectually experience the nature of and correspondences between abstract objects and categories, and thus, to realize the modal character and categorical structure of reality. Rational insight, 96 M. J. García Encinas not imagination, conceivability or linguistic competence, fallible as it might be, constitutes our only possible understanding of the modal character of reality.9 Dpartment of Philosophy 1 University of Granada Campus Cartuja 18011 Granada, Spain E-mail: encinas@ugr.es NOTES 1 There are different places where Kripke directly comments on this: "All the cases of the necessary a posteriori advocated in the text have the special character attributed to mathematical statements: Philosophical analysis tells us that they cannot be contingently true, so any empirical knowledge of their truth is automatically empirical knowledge that they are necessary. This characterization applies, in particular, to the cases of identity statements and of essence. It may give a clue to a general characterization of a posteriori knowledge of necessary truths" [Kripke (1980), p. 159.]. See also Kripke (1971), p. 88; Kripke (1980), pp. 109 & 138; or my García-Encinas (2012) which this paper aims to follow on from and extend. 2 For instance, Boghossian (1996) defends a different type of analyticity, which he calls epistemic analyticity, for a priori knowledge. In epistemic analyticity, knowledge of meaning is knowledge of truth; but meaning is not conventional: it includes different items from empirical experience. For Peacocke (1988), there is a kind of a priori knowledge for which understanding the concepts is enough to know that the sentence is true, but meaning is truthconditional rather than conventional. Hawthorne (2006) argues that deciding on the best metalanguage, where analytical truths are established, amounts to deciding between the different possible meanings of the quantifier; thus providing for its objectual reading, and for the ontological or metaphysical commitments of our theories about the world. These, and other contemporary views on analyticity, are considered in depth in Gendler & Hawthorne (2002). 3 It was Quine again, in his (1953) "Three grades of modal involvement," who once more provided the clues that led to the acknowledgement of this impossibility. 4 Categories are close to what Bealer has called semantically stable terms. However, he seems to understand categories as a special kind of concepts. He writes that "an expression is semantically stable iff, necessarily, in any language group in an epistemic situation qualitatively identical to ours, the expression The Role of Intuition in Metaphysics 97 would mean the same thing." [Bealer (1996), p. 134; my italics.] This seems to imply that intuitive knowledge of the principles that govern the categories would be conceptual knowledge, and I disagree. Intuitive knowledge could turn into propositional knowledge and, given its peculiarities, it is not rare for categories to become semantic stable terms, but their universality is not primarily explained through conceptual reasons but by pure rational insight. 5 Thus, intuition does not depend on definition or analytic/conceptual truths. As Descartes claimed, advancing the main form of what would be Quine's circularity argument against analyticity, definitions cannot provide knowledge. If someone were to say that the body is, by definition, a corporeal substance, or that a person is a rational animal, or an animated body, they would have said nothing without again defining animated body, or rational animal, or corporeal substance; and, in this way, from one single question, we would fall unwittingly into an infinite number of others. [La recherche, p. 80; Second Meditation, p. 104]. 6 This would be a nice interpretation of the words in a letter to Mersenne of 15 April 1630, where Descartes writes that "at least I think I have found a means of providing metaphysical truths in a more evident way than one can give a demonstration in Geometry" [Beck (1952), p. 9]. 7 So Markie (1998) is right in arguing that the Cogito is not a deduction, but an intuition. The intuition in the Cogito is Descartes' immediately grasping and feeling that he exists due to the simultaneously intuited premise that he doubts; and his experience that everybody else should experience the same feeling when entertaining the same thought. 8 I cannot provide a comparative account of the faculty of rational intuition as I am proposing it to be, with the different uses of "intuition" in contemporary analytic philosophy, most of which are ordinary, non-philosophical uses of the term – including cases in which intuition is appealed to for the acceptance of important philosophical theses. Nevertheless, there are some exceptions to this: one, which I have already mentioned, can be found in Lawrence BonJour; another in Charles Parsons (1980). Even if their work focuses on other fields of intuition, in induction or mathematics, both of their proposals share with mine the important point that intuitions are acts of reason and not propositions or part of the conceptual content of thoughts or images. Thus, following Chudnoff's (2011) classification of perceptualist versus doxasticist views on intuition, I would align myself with the former. 9 This paper was written thanks to the financial help received from the project FFI2011-29834-C03-02, sponsored by the Spanish Ministry of Education. I am very grateful to people at different meetings in Granada and Oporto, where I presented some of these ideas. I also thank an anonymous referee for this journal for having suggested to me a paper by Symons (2008) which offers a clarification of different contemporary uses of intuition in the literature. 98 M. J. García Encinas REFERENCES BEALER, G. (1996), 'On the Possibility of Philosophical Knowledge', Philosophical Perspectives, vol. 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