Consider the following three claims. (i) There are no truths of the form ‘p and ~p’. (ii) No one holds a belief of the form ‘p and ~p’. (iii) No one holds any pairs of beliefs of the form {p, ~p}. Irad Kimhi has recently argued, in effect, that each of these claims holds and holds with metaphysical necessity. Furthermore, he maintains that they are ultimately not distinct claims at all, but the same claim formulated in different ways. I (...) find his argument suggestive, if not entirely transparent. I do think there is at least an important kernel of truth even in (iii), and that (i) ultimately explains what’s right about the other two. Consciousness of an impossibility makes belief in the obtaining of the corresponding state of affairs an impossibility. Interestingly, an appreciation of this fact brings into view a novel conception of inference, according to which it consists in the consciousness of necessity. This essay outlines and defends this position. A central element of the defense is that it reveals how reasoners satisfy what Paul Boghossian calls the Taking Condition and do so without engendering regress. (shrink)

ABSTRACTThree experiments examined how people reason about what is possible or necessary when a conditional is true. Participants were asked to indicate whether it was necessary, possible or impossible for a specific instance to conform to one of the truth-table cases, given the truth of the conditional. It was found that most participants, inconsistently, judged the pq case as necessary but the ¬pq or ¬p¬q cases as possible. Logically, these two kinds of judgments are contradictory. Moreover, a true conditional doesn’t (...) imply that a specific instance under the conditional must be pq. Therefore, people demonstrate a necessity illusion for pq cases which contradicts their commitment to the possibility of ¬pq or ¬p¬q cases. Existing accounts of conditionals are unable to explain the contradiction and the necessity illusion. We propose an inference dissociation account and explore the theoretical implications of this necessity illusion. (shrink)

Much of what Hume calls probable reasoning is deliberate and reflective. Since there are aspects to Hume’s psychology that tempt some commentators to think, on the contrary, that for Hume all such reasoning is simple and immediate, I will be concerned to emphasize Hume’s recognition of the sophisticated sort of probable reasoning (section I). Though some of the details of my case may be new, the overall point of this section should not be news to recent scholarship. But once we (...) recognize that this reflective and deliberate reasoning constitutes a significant portion of all probable reasoning, it becomes legitimate to ask how Hume accommodates this reasoning in his psychology, his ‘science of man.’ I believe that .. (shrink)

In the nineteenth century, the separation of naturalist or psychological accounts of validity from normative validity came into question. In his 1877 Logical Studies (Logische Studien), Friedrich Albert Lange argues that the basis for necessary inference is demonstration, which takes place by spatially delimiting the extension of concepts using imagined or physical diagrams. These diagrams are signs or indications of concepts' extension, but do not represent their content. Only the inference as a whole captures the objective content of the proof. (...) Thus, Lange argues, the necessity of an inference is independent of psychological accounts of how we grasp the content of a proposition. (shrink)

The concept of “necessity of thought” plays a central role in Dag Prawitz’s essay “Logical Consequence from a Constructivist Point of View” (Prawitz 2005). The theme is later developed in various articles devoted to the notion of valid inference (Prawitz, 2009, forthcoming a, forthcoming b). In section 1 I explain how the notion of necessity of thought emerges from Prawitz’s analysis of logical consequence. I try to expound Prawitz’s views concerning the necessity of thought in sections 2, (...) 3 and 4. In sections 5 and 6 I discuss some problems arising with regard to Prawitz’s views. (shrink)

It is impossible to hold patently contradictory beliefs in mind together at once. Why? Because we know that it is impossible for both to be true. This impossibility is a species of rational necessity, a phenomenon that uniquely characterizes the relation between one person's beliefs. Here, Eric Marcus argues that the unity of the rational mind--what makes it one mind--is what explains why, given what we already believe, we can't believe certain things and must believe certain others in this (...) special sense. What explains this is that beliefs, and the inferences by which we acquire them, are constituted by a particular kind of endorsement of those very states and acts. This, in turn, entails that belief and inference are essentially self-conscious: to hold a belief or to make an inference is at the same time to know that one does. An examination of the nature of belief and inference, in light of the phenomenon of rational necessity, reveals how the unity of the rational mind is a function of our knowledge of ourselves as bound to believe the true. Rational self-consciousness is the form of mental togetherness. (shrink)

Upward monotonic semantics for necessity modals give rise to Ross’s Puzzle: they predict that □φ entails □(φ ∨ ψ), but common intuitions about arguments of this form suggest they are invalid. It is widely assumed that the intuitive judgments involved in Ross’s Puzzle can be explained in terms of the licensing of ‘Diversity’ inferences: from □(φ ∨ ψ), interpreters infer that the truth of each disjunct (φ, ψ) is compatible with the relevant set of worlds. I introduce two (...) pieces of data that this analysis fails to explain. Analyzing this data, I argue, suggests that necessity modals with embedded disjunctions license ‘Independence’ inferences: from the truth of □(φ ∨ ψ), interpreters infer that φ-without-ψ and ψ-without-φ are each compatible with the relevant set of worlds. I outline a bilateral inquisitive semantics for necessity modals that predicts the validity of the Independence inferences. I then argue that the resulting theory should be understood as one on which disjunctions denote pluralities of propositions, and necessity modals behave like collective predicates applied to these pluralities. (shrink)

Recent epistemology of modality has seen a growing trend towards metaphysics-first approaches. Contrastingly, this paper offers a more philosophically modest account of justifying modal claims, focusing on the practices of scientific modal inferences. Two ways of making such inferences are identified and analyzed: actualist-manipulationist modality and relative modality. In AM, what is observed to be or not to be the case in actuality or under manipulations, allows us to make modal inferences. AM-based inferences are fallible, but (...) the same holds for practically all empirical inquiry. In RM, modal inferences are evaluated relative to what is kept fixed in a system, like a theory or a model. RM-based inferences are more certain but framework-dependent. While elements from both AM and RM can be found in some existing accounts of modality, it is worth highlighting them in their own right and isolating their features for closer scrutiny. This helps to establish their relevant epistemologies that are free from some strong philosophical assumptions often attached to them in the literature. We close by showing how combining these two routes amounts to a view that accounts for a rich variety of modal inferences in science. (shrink)

In recent years modal syllogistic provided by 14th century logician John Buridan has attracted increasing attention of historians of medieval logic. The widespread use of quantified modal logic with the apparatus of possible worlds semantics in current analytic philosophy has encouraged the investigation of the relation of Buridan’s theory of modality with the modern developments of symbolic modal logic. We focus on the semantics of and the inferential relations among the propositions that underlie Buridan’s theory of modal syllogism. First, we (...) review all inferences between propositions of necessity, possibility, contingency, and non-contingency, with or without quod est locution, that are valid in Buridan’s semantics, and offer a comprehensive diagrammatic representation that includes them all. We then ask the question if there is a way to model those results in first order modal logic. Three ways of formalizing Buridan’s propositions in quantified modal logic are considered. Comparison of inferences between the quantified formulas and Buridan’s propositions reveals that, when supplied with a suitable formalization, Buridan’s semantics of categorical statements and immediate inferences among them can be fully captured by the quantified modal system T. (shrink)

The idea that simplicity matters in science is as old as science itself, with the much cited example of Ockham's Razor, 'entia non sunt multiplicanda praeter necessitatem': entities are not to be multiplied beyond necessity. A problem with Ockham's razor is that nearly everybody seems to accept it, but few are able to define its exact meaning and to make it operational in a non-arbitrary way. Using a multidisciplinary perspective including philosophers, mathematicians, econometricians and economists, this 2002 monograph examines (...) simplicity by asking six questions: what is meant by simplicity? How is simplicity measured? Is there an optimum trade-off between simplicity and goodness-of-fit? What is the relation between simplicity and empirical modelling? What is the relation between simplicity and prediction? What is the connection between simplicity and convenience? The book concludes with reflections on simplicity by Nobel Laureates in Economics. (shrink)

We argue that the inference from dispositional essentialism about a property (in the broadest sense) to the metaphysical necessity of laws involving it is invalid. Let strict dispositional essentialism be any view according to which any given property’s dispositional character is precisely the same across all possible worlds. Clearly, any version of strict dispositional essentialism rules out worlds with different laws involving that property. Permissive dispositional essentialism is committed to a property’s identity being tied to its dispositional profile or (...) causal role, yet is compatible with moderate interworld variation in a property’s dispositional profile. We provide such a model of dispositional essentialism about a property and metaphysical contingency of the laws involving it. (shrink)

It is thought that a valid inference to a logically necessary conclusion must proceed from entirely necessary premises. Counter-examples show this is false. Perhaps while the truth of a necessary proposition may follow from non-necessary premises, its necessity cannot so follow. Counter-examples show this to be mistaken. Must anyone who comes to know the non-necessary premises employed in the various counter-examples have prior knowledge of the necessity of the conclusions of the counter-examples? I argue against this. It is (...) true that, for any necessary proposition, there must be necessary premises from which it may validly be inferred; but no one need use these, or know these, or know how to use them, in order to know the necessity of any proposition. (shrink)

Every person acquires a worldview, a picture of reality. Within that picture, the existence of some things will be taken wholly for granted as the background to, and support of, everything else. Their existence will rarely be questioned. The cosmos or universe, the gods, God, Brahman, Heaven, the Absolute--R. T. Allen claims that all these and other world- views have been held to be that which necessarily exists and upon which all other beings depend in one way or another. European (...) philosophers, since antiquity, have offered arguments to show that their chosen candidates for the role of the necessary being or beings that support the rest of reality do actually exist. The Necessity of God sets the valid core of previous ontological arguments. It does not and cannot prove that God exists, but only that something necessarily exists. In an a priori manner and without inferring anything from what in fact exists, Allen proceeds to show that which necessarily exists is one, transfinite, eternal, and the archetype of personal existence: in short, that it is God as classically conceived. As for everything else that may exist, it must be finite and dependent for its existence upon God as its creator and sustainer. Few things are more erroneous in philosophy and disastrous in practice than artificial constructions produced without constant reference to concrete reality. That which necessarily exists may be the one exception. Before this constructive argument, Allen examines previous examples of ontological arguments in order to show exactly where they go wrong and to extract the valid core obscured within them. This will make clear the difference between them and his new version. The reader who is eager to engage the philosophical sources of belief will find a distinct treasure in The Necessity of God. (shrink)

Though clearly fallacious, the inference from determinism to fatalism (the ``Lazy Argument'''') has appealed to such minds as Aristotle and his disciple, Alexander of Aphrodisias. It is argued here (1) that determinism does entail a rather similar position, dubbed ``futilism''''; and (2) that distinctively Aristotelian determinism entails fatalism for any event to which it applies. The concept of ``fate'''' is examined along the way.

The common method of the traditional Islamic Jurisprudence in seminaries has been challenged by Ayatollah Yousef Saanei, one of the ten prominent Iranian Grand Ayatollahs. Saanei is well known for attempting to institutionalize a new method of Ijtihad, known as searching Ijtihad, which seeks to reconsider the common mode of understanding religious texts and jurisprudential inferences. His experiences of observing the systematic ineffectiveness and discrimination in popular jurisprudence regarding women’s rights, family, and religious minorities persuaded him to take scientific (...) action in revising the common jurisprudential method. In the present paper, the necessity of revising the common jurisprudential approach in seminaries from Saanei’s point of view is firstly studied. Afterwards, the foundations, principles, and methods of modern Saanei’s Ijtihad will be investigated to determine the structure and foundations of his jurisprudential method and evaluate its impact on resolving the contradictions between traditional perceptions of religion and human rights. (shrink)

The idea that simplicity matters in science is as old as science itself, with the much cited example of Ockham's Razor, 'entia non sunt multiplicanda praeter necessitatem': entities are not to be multiplied beyond necessity. A problem with Ockham's razor is that nearly everybody seems to accept it, but few are able to define its exact meaning and to make it operational in a non-arbitrary way. Using a multidisciplinary perspective including philosophers, mathematicians, econometricians and economists, this 2002 monograph examines (...) simplicity by asking six questions: what is meant by simplicity? How is simplicity measured? Is there an optimum trade-off between simplicity and goodness-of-fit? What is the relation between simplicity and empirical modelling? What is the relation between simplicity and prediction? What is the connection between simplicity and convenience? The book concludes with reflections on simplicity by Nobel Laureates in Economics. (shrink)

It is often remarked that Indian logic (IL) has no conception of necessity. But what kind of necessity is absent in this system? Logical necessity is presumably absent: the structure of the logical argument in IL is often given as a reason for this claim. However even a cursory understanding of IL illustrates an abiding attempt to formulate the idea of necessity. In Dharmakīrti's classification of inferences, one can detect the formal process of entailment in (...) the inferences arising from class inclusion. In Western philosophy, Leibniz's invocation of 'contingent necessity' as distinguished from the 'necessary necessity' is part of a tradition that finds value in the idea of contingent necessity. In contemporary philosophy, this has been championed by Armstrong, specifically in the context of understanding the necessity inherent in scientific laws. In IL, the analysis of 'invariable concomitance' (vyāpti) is of crucial importance and its definitions are very complex. This paper argues how vyāpti can be understood in terms of contingent necessity and also how the complex definitions can be interpreted as an attempt to define contingent necessity in terms of 'logical' necessity. (shrink)

In chapter 9 of De Interpretatione, Aristotle offers a defense of free will against the threat of fatalism. According to the traditional interpretation, Aristotle concedes the validity of the fatalist's arguments and then proceeds to reject the Principle of Bivalence in order to avoid the fatalist's conclusion. Assuming that the traditional interpretation is right on this point, it remains to be seen why Aristotle felt compelled to reject such an intuitive semantic principle rather than challenge the fatalist's inference from truth (...) to necessity. The answer, I contend, lies in Aristotle's theory of truth and truthmakers. (shrink)

Analytical commentary -- Fruits upon one tree -- The continuation of the early draft into philosophy of mathematics -- Hidden isomorphism -- A common methodology -- The flatness of philosophical grammar -- Following a rule 185-242 -- Introduction to the exegesis -- Rules and grammar -- The tractatus and rules of logical syntax -- From logical syntax to philosophical grammar -- Rules and rule-formulations -- Philosophy and grammar -- The scope of grammar -- Some morals -- Exegesis 185-8 -- Accord (...) with a rule -- Initial compass bearings -- Accord and the harmony between language and reality -- Rules of inference and logical machinery -- Formulations and explanations of rules by examples -- Interpretations, fitting and grammar -- Further misunderstandings -- Exegesis 189-202 -- Following rules, mastery of techniques and practices -- Following a rule -- Practices and techniques -- Doing the right thing and doing the same thing -- Privacy and the community view -- On not digging below bedrock -- Private linguists and private linguists : Robinson Crusoe sails again -- Is a language necessarily shared with a community of speakers? -- Innate knowledge of a language -- Robinson Crusoe sails again -- Solitary cavemen and monolinguists -- Private languages and private languages -- Exegesis 203-37 -- Agreement in definitions, judgements, and form of life -- The scaffolding of facts -- The role of our nature -- Forms of life -- Agreement : consensus of human beings and their actions -- Exegesis 238-42 -- Grammar and necessity -- Setting the stage -- Leitmotifs -- External guidelines -- Necessary propositions and norms of representation -- Concerning the truth and falsehood of necessary propositions -- What necessary truths are about illusions of correspondence : ideal objects, kinds of reality, and ultra-physics -- The psychology of the A priori -- Knowledge -- Belief -- Certainty -- Surprise -- Discoveries and conjectures -- Compulsion -- Propositions of logic and laws of thought -- Alternative forms of representation -- The arbitrariness of grammar -- A kinship to the non-arbitrary -- Proof in mathematics -- Conventionalism. (shrink)

This chapter contains sections titled: Validity and Necessity The Validity Paradox Gödel Arithmetizing the Validity Paradox The Validity Paradox in S5 Validity, Necessity, and Deductive Inference.

This paper is concerned with counterfactual logic and its implications for the modal status of mathematical claims. It is most directly a response to an ambitious program by Yli-Vakkuri and Hawthorne (2018), who seek to establish that mathematics is committed to its own necessity. I claim that their argument fails to establish this result for two reasons. First, their assumptions force our hand on a controversial debate within counterfactual logic. In particular, they license counterfactual strengthening— the inference from ‘If (...) A were true then C would be true’ to ‘If A and B were true then C would be true’—which many reject. Second, the system they develop is provably equivalent to appending Deduction Theorem to a T modal logic. It is unsurprising that the combination of Deduction Theorem with T results in necessitation; indeed, it is precisely for this reason that many logicians reject Deduction Theorem in modal contexts. If Deduction Theorem is unacceptable for modal logic, it cannot be assumed to derive the necessity of mathematics. (shrink)

This discussion paper is a reply to Stathis Psillos’ paper “Induction and Natural Necessities” :327–340, (2017), published in this journal. In that paper, he attempts to refute David Armstrong’s solution to the problem of induction. To accomplish this desideratum, he proposes that the best explanation for our observed regularities is a sort of “best before date” necessity. That is, necessary connections may break down and are not by default timeless. He develops arguments against my :67–82, (2014) defence of the (...) necessitarian solution regarding a previous paper by Beebee :504–527, 2011.. He alleges that best before date necessity is no worse than timeless necessity; his proposal does not imply any further inductive generalisation to timeless necessity; and inductive inferences are justified. In this discussion paper, I provide arguments against these three claims. (shrink)

This paper seeks to explicate and analyze an alternative response to fine-tuning arguments from those that are typically given—namely, design or brute contingency. The response I explore is based on necessity, the necessitarian response. After showing how necessity blocks the argument, I explicate the reply I claim necessitarians can give and suggest how its three requirements can be met: firstly, that laws are metaphysically necessary; secondly, that constants are metaphysically necessary; and thirdly, that the fundamental properties that determine (...) the laws and constants are necessary. After discussing each in turn, I end the paper by assessing how the response fares when running the fine-tuning argument in two ways, as an inference to best explanation and as a Bayesian argument. (shrink)

The book is an epistemological monograph written from a multidisciplinary perspective. It provides a complex and realistic picture of cognition and rationality, as endowments aimed at making sense and reacting smartly to one's environment, be it epistemic, social or simply ecological. The first part of the book analyzes scientific modeling as products of the biological necessity to cope with the environment and be able to draw as many inferences as possible about it. Moreover, it develops an epistemological framework (...) which will be exploited in both the second part of the book, focusing on social cognition and cognitive niche construction, and the third part, dealing with the apparent irrationality of magical and religious belief. The book also discusses how both social networking and online religion influence cognition, rationality and irrational belief. (shrink)

Discontented people might talk of corruption in the Commons, closeness in the Commons and the necessity of reforming the Commons, said Mr. Spenlow solemnly, in conclusion; but when the price of wheat per bushel had been the highest, the Commons had been the busiest; and a man might lay his hand upon his heart, and say this to the whole world, – ‘Touch the Commons, and down comes the country!’.

SummaryThis article argues that Archibald Campbell's Necessity of Revelation can be viewed as the first application of the ‘science of human nature’, a characteristic branch of the Scottish Enlightenment, to the study of religious belief. Adopting Baconian and Newtonian methodological principles, Campbell set hypotheses, collected historical data, and inferred conclusions about the capabilities of human nature to come to fundamental religious ideas without the aid of revelation. He did so not only to reject the ‘deist’ position on the powers (...) of unassisted human reason, associated with Matthew Tindal's Christianity as Old as the Creation, but also to refute Campbell's conservative critics within the Church of Scotland who had earlier tried him for heresy. Campbell's example is that of a university professor using the experimental study of religion to defeat both radical freethinking and Calvinist orthodoxy. His work is another instance of the complicated relationship between science and religion within eighteenth-century Scotland. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:47. Hausman on Certainty and Necessity in Hume Professor Hausman in the course of a painstaking and often illuminating examination of my paper "Hume on Intuitive and Demonstrative Inference" fortunately has occasion to make some positive suggestions of his own regarding the best way to interpret Hume's philosophy. One of the most interesting and provocative of these suggestions is that we should discount Hume's claim to have found (...) an impression of reflection which is at the same time one of necessity. Rather, we should regard the impression of reflection in question as one of certainty. Such a manner of proceeding would, moreover, in Hausman' s view have the advantage öf explaining why we all believe that causal connections are necessary when in fact they are not. For the same impression of certainty, as Hausman envisages it, will be generated by both the cognitive act of comparing two relata wherein genuine necessity is reflected and the determination of an idea by a preceding impression wherein causal inference consists and wherein genuine necessity plays no role. But how can Hausman be so sure that they will be the same? For he insists that the cognitive act of comparing two relata is radically different from the determination of an idea by a preceding impression. Why then should we expect that observation of the two should generate comparable feelings of certainty? And if they do not generate comparable feelings of certainty what is the purpose served by postulating them? Moreover, I use the term "postulating" advisedly: by Hausman' s own admission there is little or no textual evidence for their presence in Hume's theory of causal inference. Hausman' s purpose would be no worse served - at least incoherence would be avoided - by emphasizing what a cognitive act of comparing two relata and a determination of an idea by a preceding impression have in common as opposed to what distinguishes them. They have, moreover, more in 48. common than he seems to think. For, while the one requires reflection according to Hume and the other does not, they 2 both involve a determination of the mind. Nor is Hume's use of the concept of intuition in connection with the former incompatible with such a determination, as Hausman seems to think. On the contrary, it implies it. For intuition as Hume understands it seems to pertain to immediate inference. And such inferences consist as far as he is concerned in determinations of the mind to move from one 3 idea to a second one. Indeed, it is just the supposed infallibility of such determinations that allows him to distinguish them from the more haphazard principles of as4 sociation. A cognitive act of comparing two relata and a determination of an idea by a preceding impression are sufficiently alike, then, to explain why we all believe that causal connections are necessary when in fact they are not. This does not mean, of course, that necessity need reside in such a cognitive act of comparing. As a matter cf fact, as we shall see in a moment, this is not the view that Hume usually takes of the matter. But a cognitive act of comparing, as we shall also see in a moment, is close enough to the area in which necessity does reside to allow Hume to explain in the manner indicated how our mistaken belief about causal connections arises. Hausman' s comparable feelings of certainty are not required. Nor has Occam's razor finished cutting. More specifically, the idea of real necessity of which Hausman speaks could have, as far as I can see, no role to play in Hume's philosophy which is not already played by the cognitive act of comparing two relata. There is, moreover, no such idea anymore than there is any idea of causal necessity. The "idea of entities in a particular sort of relation" presumably like resemblance will not do. For resemblance is not necessity. And to say as Hausman does that "it is because we can read off a resemblance, say, that we pronounce the relationship necessary" is to state a problem, not to 49.??. 6 solve it. What then is the solution? It seems... (shrink)

An examination of a particular passage in Cicero's De fato—Fat. 13–17—is crucial to our understanding of the Stoic theory of the truth-conditions of conditional propositions, for it has been uniquely important in the debate concerning the kind of connection the antecedent and consequent of a Stoic conditional should have to one another. Frede has argued that the passage proves that the connection is one of logical necessity, while Sorabji has argued that positive Stoic attitudes toward empirical inferences elsewhere (...) suggest that that cannot be the right interpretation of the passage. I argue that both parties to the debate have missed a position somewhere between them which both renders a connection between antecedent and consequent that is not merely empirical and makes sense of the actual uses to which the Stoics put the conditional. This will be an account which grounds the connection between antecedent and consequent in a prolêpsis, a special kind of concept which plays a special epistemological role for the Stoics, especially in grounding scientific explanations. My contention will be that Stoic conditionals are true when there is a conceptually necessary connection between antecedent and consequent such that the former explains the latter via a prolêpsis. (shrink)

This article provides the first comprehensive reconstruction and analysis of Hintikka’s attempt to obtain a measure of the information yield of deductive inferences. The reconstruction is detailed by necessity due to the originality of Hintikka’s contribution. The analysis will turn out to be destructive. It dismisses Hintikka’s distinction between surface information and depth information as being of any utility towards obtaining a measure of the information yield of deductive inferences. Hintikka is right to identify the failure of (...) canonical information theory to give an account of the information yield of deductions as a scandal, however this article demonstrates that his attempt to provide such an account fails. It fails primarily because it applies to only a restricted set of deductions in the polyadic predicate calculus, and fails to apply at all to the deductions in the monadic predicate calculus and the propositional calculus. Some corollaries of these facts are a number of undesirable and counterintuitive results concerning the proposed relation of linguistic meaning (and hence synonymy) with surface information. Some of these results will be seen to contradict Hintikka’s stated aims, whilst others are seen to be false. The consequence is that the problem of obtaining a measure of the information yield of deductive inferences remains an open one. The failure of Hintikka’s proposal will suggest that a purely syntactic approach to the problem be abandoned in favour of an intrinsically semantic one. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:IT AIN'T NECESSITY, SO... (With Apologies to George Gershwin) I shall argue in this paper that what Hume calls the idea of necessary connection is mislabelled, and that what he ought to call the idea of necessary connection is not so labelled. My argument is not that there are, on Hume's view, real necessary connections between causes and their effects but rather that there is an idea of (...) genuine necessary connection — what I call logical necessity — which we all mistakenly believe extends to causal connections. The genesis of this mistake is given a psychological explanation in the Treatise. Precisely how does Hume account for the origin of what he calls our idea of necessary connection? I have argued elsewhere that, whatever the answer, it has little philosophical importance. My reason was that, given Hume's view that causal connections are not necessary, the question must be viewed as one within psychology. Recent work on Hume, however, has convinced me that my former opinion was much too quick. Imlay, for example, has challenged Hume's distinction between demonstrative and probable inference on the grounds that Hume gives only one account of necessity for both 2 mathematical and lawlike truths. As I now see much more clearly, there are important philosophical distinctions that must be made in any full explication of Hume's view of the origin of our idea of causal necessity. I shall attempt an answer to the lead question of the second paragraph. My strategy is as follows. I shall first present a synopsis of Hume's account of our belief in causal necessity. Next, I shall develop 87. 88. a view of logical necessity. Finally, I shall briefly examine the exact genesis of the confusion between logical and causal necessity. Consider the following three propositions: (1)Hume does not believe that there are necessary causal connections. (2)All statements of laws of nature are on Hume's view descriptions of constant conjunctions, the logical form of which is captured by the Russellian " (x) [fx => gx]." (3)This logical form captures Hume's first definition of "cause." On these three propositions I and many other philosophers agree. I and an ever-shrinking number of philosophers also believe that Hume is right. But everyone, according to Hume, in some sense believes that causal connections are necessary; the Humean philosopher knows they are not but acts otherwise, while the ordinary person simply acts without the knowledge. Since everyone believes what is false, only a psychological explanation can be given for why we believe it anyway. Thus, Hume's second definition of "cause", and the view that the idea of necessity arises from the determination of the mind to pass from the impression of a cause to an idea of 3 its effect. The three most salient passages from the Treatise on the production of the idea of necessary connection follow. As we shall see, these passages cannot be understood without considering a number of others. For after a frequent repetition, I find, that upon the appearance of one of the objecte, the mind is determin 'd by custom to consider its usual attendant, and to consider it in a stronger light upon account of 89. its relation to the first object. 'Tis this impression, then, or determination, which affords me the idea of necessity. (T 156) Tho ' the several resembling instances, which give rise to the idea of power, have no influence on each other, and can never produce any new quality in the object, which can be the model of that idea, yet the observation of this resemblance produces a new impression in the mind, which is its real model. For after we have observ 'd the resemblance in a sufficient number of instances, we immediately feel a determination of the mind to pass from one object to its usual attendant, and to conceive it in a stronger light upon account of that relation. This determination is the only effect of the resemblance; and therefore must be the same with power or efficacy, whose idea is deriv 'd from the resemblance. The several instances of resembling conjunctions leads us into the notion of power and necessity.... Necessity, then... (shrink)

I examine how Kant argues for the transcendental ideality of space. I defend a reading on which Kant accepts the ideality of space because it explains our (actual) knowledge that mathematical judgments are necessarily true. I argue that this reading is preferable over the alternative suggestion that Kant can infer the ideality of space directly from the fact that we have an a priori intuition of space. Moreover, I argue that the reading I propose does not commit Kant to incoherent (...) modal views. If we carefully distinguish between different senses of modality, the fact that our spatial form of intuition is (in some sense) contingent does not undermine the claim that this form can explain how our mathematical judgments are (in some sense) necessary. (shrink)

Quantification, understood in the widest possible sense, is a phenomenon of fundamental interest for logic and linguistics and at the same time a phenomenon whose exegesis presents notorious problems in both of these disciplines. The general point to be made in the present essay is this: that there is a lack of understanding of the real nature of quantification, both in natural language and in logic itself, and that this is a direct consequence of a serious defect in Morris’s division (...) of semiotics into three autonomous branches of syntax, semantics, and pragmatics, the study of each of which is supposed to proceed independently of the study of any other. The aim of this paper is thus twofold: on the one hand to show that the real exegesis of quantification may be attained only under a certain interpretation of semiotics as such; and on the other hand to show that the very fact of the attainability of this authentic explanation of the nature of quantification gives grounds to speak of the necessity of reassessing certain notions on which logic, linguistics, and semiotics are currently based. (shrink)

John Foster; VI*—Induction, Explanation and Natural Necessity, Proceedings of the Aristotelian Society, Volume 83, Issue 1, 1 June 1983, Pages 87–102, https://d.

Contemporary evolutionary theory, derived from the intellectual marriage of Darwin's and Mendel's discoveries, leads us to view organisms as successful, but essentially ad hoc, responses to chance and necessity. Biological universals, the code, the pentadactyl limb, are frozen accidents shared by descent. The source of biological order has come to be seen as selection itself. This paper argues that this view is fundamentally inadequate. It ignores those underlying sources of biological order which derive from the generic self-organizing properties of (...) the biological building blocks. Among these generic properties are almost universal aspects of phase resetting responses in biological rhythmic systems, fascinating properties of continuity, symmetry and handedness seen in pattern regeneration across distant phyla; and statistically robust properties expected of eukaryotic gene regulatory systems persistently subject to mutations which "scramble" regulatory interactions. These examples suggest that many properties in organisms reflect a balance between selection, and the rich generic properties which would occur in the absence of selection. Where the balance is "close" to generic, a new pattern of evolutionary inference, and an ahistorical source of biological universals may be found: Those properties reflect, not selection, but the self-organizing features of the building blocks. (shrink)

I begin by defending condition (i) against five objections (section 2). Following this, I show that the theory that laws obtain contingently encounters three problems that are solved by the theory that laws are metaphysically necessary (section 3). In section 3, I criticize the regularity theory of natural laws and the universals theory of Armstrong, Dretske and Tooley, and also show how the metaphysical theory solves the “inference problem” that Van Fraassen (1989) posed for any theory of natural laws.

One of the issues of discussion between Ahl al-Sunnah and the Mu‛tazila, who differ in many issues, is the relationship between divine command and divine will. Among those who express their opinion on is the Ash‛arī theologian Salmān al-Nīsābūrī. The author, who first cites his sect’s approach on this issue and then explains that Mu‛tazila’s contrary view, adopted the view that the belief, which follows as worship and good deeds commanded by Allah will be the same from his servants. In (...) this matter he basically elaborates three arguments the Mu‛tazila. He states that they build the first of these proofs on the impossibility of the commandment and the will being in a separate direction, and secondly on the fact that the desire for evil is bad. Finally, he adds that they bring evidence from the verses which translates as Allah desires the good of his servants and doesn’t intend his evil deeds. Nīsābūrī, doesn’t pass on these Mu‛tazilite proofs with an immediate answer, but also puts on his agenda possible other objections to those answers that he is giving. He makes the debate very comprehensive, especially on the first evidence he attributes to them. In this sense, he tries to refute the Mu‛tazila argument that the ruler cannot have a will contrary to what he ordered, based on some other rulers who would not want their orders to be fulfilled. Nīsābūrī, who cites some other objections on this issue, states that while there are claims regarding the necessity of order-will harmony, it isn’t consistent that these claimants develop their objections to the examples that show the opposite of their views. In other words, he says that these regarding cases invalidate Mu‛tazila’s claim of necessity. Nīsābūrī includes abrogation in the later stages of the debate and argues that abrogation, which means the abolition of a decree, hits a blow to their understanding of the necessity of order-will. The author also takes objections to his agenda and responds to them. He also examines Mu‛tazila’s approach on the content that if the will is contrary to the order, the rebel and the submissive will be confused, so they must be compatible. Since this claim confirms the meaning that the unbelievers obey Allah’s will with their blasphemy, he makes explanations that obedience will be achieved by order, not by will. On the other hand, the author tries to bind his interlocutors by emphasizing that there’s no room for discussion when it is seen at the relevant verses and seen that Allah doesn’t wish (some) unbelievers to believe. Nīsābūrī, also examines the argument made by Mu‛tazila as to the necessity of conformity between divine command and divine will, that wishing for evil is also evil. Nīsābūrī, who makes relatively more concise explanations on this subject, pointing to the source of this evidence and stating that it is reached from the realm of the perceptible (qiyas bi’l-shāhid). Then, he makes some explanations that the visible realm and the invisible realm cannot be evaluated in the same way and draws attention to the fact that Allah’s being unwise isn’t inferred from the worldly affairs that are happening against Muslims. Nīsābūrī also deals with Mu‛tazila’s evidence for the harmony of divine will and divine order through verses stating that Allah wouldn’t wish his servants to harm. At this stage, he makes comments that the relevant verses are suitable to be evaluated in another way. For this, sometimes makes linguistic explanations, sometimes refers to the content of other verses, and sometimes points to the meaning of the verse used as the evidence. In all of them, he ultimately tries to show that the verses raised by Mu‛tazila do not support their claim. While the author refutes those evidences, he also points out the problems that may arise if the view defended by Mu‛tazila would accepted. In this sense, Nīsābūrī points out that this view will also mean the occurrence of deeds that Allah does not want, and this would bring harm to the divine judgement. As a result, Nīsābūrī underlines that at least Allah’s order towards His servants, whom He knows won’t believe, isn’t in the same direction. (shrink)

Julien Tricard tackles the abductive solution to the problem of induction. In order to best explain the regularities that can be observed in nature, should one assume that they necessarily result from natural laws, without which they would be improbable cosmic coincidences? By examining David Armstrong's and John Foster's versions of this inference, Julien Tricard shows that it is based on the confusion of two incompatible concepts of “regularity”. From this he derives a conception of induction that is neither the (...) empiricists’ factual generalization, nor the abduction of nomic necessities from observed regularities, but the operation of constituting particular facts as regular instances of laws. (shrink)

This paper addresses Frege's discussion of illogical thought in the introduction to Basic Laws of Arithmetic. After a brief introduction, I discuss Frege's claims that logic is normative vis-à-vis thought, and not descriptive, and his opposition to the idea that logical laws express psychological necessities. I argue that these two strands of Frege's polemic against psychologism constitute two motivating factors behind his allowing for the possibility of illogical thought. I then explore a line of thought—originally advanced by Joan Weiner—according to (...) which Frege should have rejected illogical thought as not constituting a genuine possibility. I argue that, once developed, this line of thought constitutes an important correction (moreover, one that is consistent with his two aforementioned anti-psychologistic strands) to Frege's own response to the possibility of illogical thought. -/- . (shrink)

What is the source of the hardness of the logical must? What does the necessity of mathematical and logical inference consist in? If I am plotting the curve y = x2 and assume that x = 2 I must conclude that y = 4; no other consequence can be drawn. What is the nature of this ‘must'?Understanding Wittgenstein's answer to this question is essential to understanding his later philosophy. The question of the nature of logical or mathematical necessity (...) is as fundamental for the Investigations as it obviously was for the Tractatus. Barry Stroud's article “Wittgenstein and Logical Necessity” certainly is still one of the most illuminating and important of the papers dealing with this question. (shrink)

In the Posterior Analytics (I 6, 75a18–27) Aristotle discusses a puzzle which endangers the possibility of inferring a non-necessary conclusion. His solution relies on the distinction between the necessity of the conclusion's being the case and the necessity of admitting the conclusion once one has admitted the premisses. The former is a factual necessity, whereas the latter is meant to be a normative or deontic necessity that is independent of the facts stated by the premisses and (...) the conclusion. This paper maintains that Aristotle resorts to this distinction because he thinks that, as long as it is conceived as a factual relation, logical consequence cannot exist independently of the facts expressed by the premisses and the conclusion. As a corollary, the necessity of such a consequence relation always requires the necessity of these facts. Aristotle holds this factual conception of logical consequence responsible for the puzzle, since it cannot account for valid syllogisms with contingent or false premisses. The alternative conception of necessity is then introduced by him in order to make good this deficiency. The distinction between the necessity of being and the necessity of saying was revived by the Oxford logician E. W. B. Joseph, and taken over by Frank Ramsey in his seminal Truth and Probability, but has not received attention from recent interpreters of Aristotle's logic. This paper, however, argues that, in spite of its intrinsic interest, the distinction bore no significant fruit in Aristotle's logical doctrine. (shrink)

Aristotle’s Prior Analytics identifies deductions simpliciter with inferential necessity, so that a deduced conclusion is necessarily inferred from some premises. Modern logical reconstructions claim that inferential necessity in Aristotle corresponds to logical validity. However, this logical reconstruction fails on two accounts. First, logical validity does not highlight Aristotle’s distinction between inferential necessity and predicative necessity, meaning that the inferential necessity of a deduction is not of the same kind as the predicative necessity of a (...) non‑deductive argument. Second, logical validity does not explain the relevance of Aristotle’s distinction between complete and incomplete deductions. Logicians speak of complete deduction by adding the term “obvious” or “transparent” to logical validity, and then criticize Aristotle’s view for being unclear. However, Aristotle’s position is not confronted with this difficulty. There is nothing to add to inferential necessity, which already means complete deducibility, as opposed to incomplete deducibility, deemed to be potentially complete. Accordingly, the Prior Analytics reduces the incomplete deductions to the complete deductions in order to prove the potential, inferential necessity of the incomplete deductions. Logical validity would have been faithful to Aristotle’s text, if it had been possible to coin a notion of potential validity, distinct from both validity and invalidity. (shrink)

The New Semantics (NS) introduced by Kripke and Putnam is often thought to block antiphysicalist arguments that involve an inference from an explanatory gap to a failure of supervenience. But this “NS Rebuttal” depends upon two assumptions that are shown to be dubious. First, it assumes that mental-kind terms are among the kinds of terms to which NS analysis is properly applied. However, there are important differences in this regard between the behavior of notions like ‘pain’ and notions like ‘water’, (...) as Kripke himself has argued. Second, even on the assumption that NS analysis is appropriate to mental-kind terms, it is further assumed that this would block the anti-physicalist premise that an abiding and principled explanatory gap would entail a failure of metaphysical supervenience. But the paradigm examples of NS analysis show nothing of the sort. What they show is that there are a posteriori necessities (e.g., “water contains hydrogen”) that cannot be inferred from the sense of natural kind terms. But they do not show that such necessities cannot be derived from an adequate scientific understanding of the phenomena in question. Indeed, such derivations are often available with kinds like water, but seem unavailable with mental kinds like ‘pain’ and ‘belief’. (shrink)

Johnston maintains that the notion of a proposition -- ”a language independent (abstract) particular” -- can be dispensed with in philosophical semantics and replaced with that of a propositional act. A propositional act is a component of a speech act that is responsible for the propositional content of the speech act. Traditionally, it is thought that a propositional act yields the propositional content of a speech act by being an act of expressing a proposition. And it is the expressed proposition (...) that serves as the propositional content of the speech act. Johnston points out, however, that a propositional act is a structured event consisting minimally of a referential act, a predicative act, and a time-designative act. And on Johnston's view, the propositional content is the structured propositional act itself. (Strictly speaking, Johnston analyzes sameness of propositional content in terms of sameness of propositional act type, from which I, perhaps rashly, inferred that the propositional content of a speech act should be taken to be the propositional act itself). Johnston argues that a semantic analysis in terms of propositional acts enables us to reconcile the necessity of both, (1) Hesperus is Phosphorus (2) Phosphorus is Phosphorus with their intuitive difference in meaning, while maintaining the direct reference theory of proper names. Moreover, he argues that invoking propositional acts rather than propositions has the advantage of being able to capture the various senses in which distinct statements might be said to "say the same thing", as well as that of ontological parsimony. I will address each of these claims in turn, but first, I want to point out that the propositionalist can easily reconcile the necessity of (1) and (2) with their intuitive difference in meaning, without forsaking direct reference. All one needs to do is invoke the Fregean idea that there is a meaning shift in “thatâ€-clauses of (opaque) indirect discourse (and other) ascriptions.. (shrink)

Dans mon article, je soutiens qu'il existe une voie epistemique fiable qui mène de la connaissance des verités conceptuelles a celle des nécessites métaphysiques. Dans un premier temps, je montre que nous pouvons prétendre connaitre des vérites conceptuelles dans la mesure ou nous savons à quelles conditions nos termes (ou du moins un grand nombre d'entre eux) s'appliquent. Je défends notamment cette idée face a un argument récent que Williamson adresse a la conception épistémique de l'analyticite. Dans un second temps, (...) je montre que notre connaissance des vérités conceptuelles constitue un moyen fiable de connaitre des nécessités métaphysiques. En effet, de deux choses l'une : ou bien la connaissance conceptuelle conduit directement a la connaissance de nécessités métaphysiques ; ou bien, lorsque ce n'est pas le cas, nous pouvons du moins savoir qu'une telle inférence n'est pas permise, en vertu d une réflexion purement sémantique, « depuis notre fauteuil» (armchair). J'en conclus que la connaissance conceptuelle constitue un moyen sur d'acquérir des connaissances modales. (shrink)