Inference

Inferential Internalists accept the Principle of Inferential Justification (PIJ), according to which one has justification for believing P on the basis of E only if one has justification for believing that E makes probable P. Richard Fumerton has defended PIJ by appeal to examples, and recently Adam Leite has argued that this principle is supported by considerations regarding the nature of responsible belief. In this paper, I defend a form of externalism against both arguments. This form of externalism recognizes what (...) I call the phenomenon of reflective defeat: if one is justified in not believing that E makes probable P, then this defeats whatever justification one has for believing P upon the basis of E. I argue that this modified version of externalism has the virtue of accommodating the intuitions that motivate internalism, without the cost of the vicious regress that makes internalism so unattractive. (shrink)

In this essay we argue that reasoning can sometimes generate epistemic justification, rather than merely transmitting justification that the subject already possesses to new beliefs. We also suggest a way to account for it in terms of the relationship between epistemic normative requirements, justification and cognitive capacities.

Knowledge can be transmitted by a valid deductive inference. If I know that p, and I know that if p then q, then I can infer that q, and I can thereby come to know that q. What feature of a valid deductive inference enables it to transmit knowledge? In some cases, it is a proof of validity that grounds the transmission of knowledge. If the subject can prove that her inference follows a valid rule, then her inference transmits knowledge. (...) However, this only pushes the question back to the inference that was made in this proof. What feature of that inference enables it to transmit knowledge? A vicious regress looms here. Every proof requires a valid inference, and every valid inference must follow at least one rule of inference. So every proof must follow at least one rule of inference. Therefore not every valid inference that transmits knowledge can acquire this power through a proof, on pain of vicious infinite regress. So it must be possible to transmit knowledge by making an inference that follows an underived rule. A deductive inference that follows an underived rule is what I will call a basic deductive inference. It must be possible to transmit knowledge by making a basic deductive inference. But how is this possible? What feature of a basic deductive inference gives it this power to transmit knowledge? (shrink)

Here we challenge the orthodoxy according to which abduction is an a posteriori mode of inference. We start by providing a case study illustrating how abduction can justify a philosophical claim not justifiable by empirical evidence alone. While many grant abduction's epistemic value, nearly all assume that abductive justification is a posteriori, on grounds that our belief in abduction's epistemic value depends on empirical evidence about how the world contingently is. Contra this assumption, we argue, first, that our belief in (...) abduction’s epistemic value is not and could not be justified a posteriori, and second, that attention to the roles experience plays in abductive justification supports taking abduction to be an a priori mode of inference. We close by highlighting how our strategy for establishing the a priority of abduction positively contrasts with strategies in Bonjour (1998), Swinburne (2001), and Peacocke (2004) aiming to establish the a priority of certain ampliative modes of inference or abductive principles. (shrink)

The paper asks under what conditions deductive reasoning transmits justification from its premises to its conclusion. It argues that both standard externalist and standard internalist accounts of this phenomenon fail. The nature of this failure is taken to indicate the way forward: basic forms of deductive reasoning must justify by being instances of ‘blind but blameless’ reasoning. Finally, the paper explores the suggestion that an inferentialist account of the logical constants can help explain how such reasoning is possible.

Epistemic relativism has the contemporary academy in its grip. Not merely in the United States, but seemingly everywhere, most scholars working in the humanities and the social sciences seem to subscribe to some form of it. Even where the label is repudiated, the view is embraced. Sometimes the relativism in question concerns truth, sometimes justification. The core impulse appears to be a relativism about knowledge. The suspicion is widespread that what counts as knowledge in one cultural, or broadly ideological, setting (...) need not count as knowledge in another. (shrink)

This paper addresses the extent to which quotidian cognition is like scientific inference by focusing on Jerry Fodor's famous analogy. I specifically consider and rebut a recent attempt made by Tim Fuller and Richard Samuels to deny the usefulness of Fodor's analogy. In so doing, I reveal some subtleties of Fodor's arguments overlooked by Fuller and Samuels and others. Recognizing these subtleties provides a richer appreciation of the analogy, allowing us to gain better traction on the issue concerning the extent (...) to which everyday cognition is like scientific inference. In the end, I propose that quotidian cognition is indeed like scientific inference, but not precisely in the way Fodor claims it is. (shrink)

A survey of contemporary philosophical and scientific literatures reveals that different authors employ the term ‘heuristic’ in ways that deviate from, and are sometimes inconsistent with, one another. Given its widespread use in philosophy and cognitive science generally, it is striking that there appears to be little concern for a clear account of what phenomena heuristics pick out or refer to. In response, I consider several accounts of ‘heuristic’, and I draw a number of distinctions between different sorts of heuristics (...) in order to make sense of various research programmes. I then develop a working characterization of ‘heuristic’ which is shown to be coherent and robust enough to serve as a kind within philosophy and cognitive science broadly. My intent is not to pursue a unified account of ‘heuristic’, but to highlight some features of certain kinds of heuristics that are important for theorizing about cognition in order to proceed with a science of the mind/brain. 1 Why We Need an Appropriate Characterization of ‘Heuristic’2 Inadequate Definitions2.1 A positive attempt2.2 Heuristics versus guaranteed correct outcomes3 A Taxonomy of Heuristics3.1 Stimulus-driven versus heuristic3.2 Perceptual versus cognitive heuristics3.3 Computational versus cognitive heuristics3.4 Methodological versus inferential heuristics3.5 Summary of distinctions4 Characterizing Cognitive Heuristics4.1 Heuristics as rules of thumb4.2 Beyond rules of thumb: exploiting information5 Concluding Remarks. (shrink)

NOTE: this is a substantial revision of a previously uploaded draft. Intuitions are often thought of as inputs to theoretical reasoning. For example, you might form a belief by taking an intuition at face value, or you might take your intuitions as starting points in the method of reflective equilibrium. The aim of this paper is to argue that in addition to these roles intuitions also play action-guiding roles. The argument proceeds by reflection on the transmission of justification through inference. (...) According to inferential internalists, in order to gain justification for believing the conclusion of an argument by inferring it from the premises in that argument one must “see” that the premises support the conclusion. I motivate this view and endorse the idea that one’s “seeing” such a support relation consists of one’s having an intuition. In a number of recent papers, Paul Boghossian has pressed a regress argument against inferential internalism inspired by Lewis Carroll’s dialogue “What the Tortoise Said to Achilles.” I develop a response to Bogossian’s argument according to which intuitions work like mental imperatives and inferences are mental actions performed by obeying them. After developing this response to Boghossian’s argument, I take up the question of what it is in virtue of which intuitions play a guidance role, when they do so. (shrink)

Standard definitions of validity are designed to preserve truth from the premises to the conclusion. However, it seems possible to construct arguments that contain sentences in the imperative mood. Such sentences are incapable of being true or false, so the standard definitions cannot capture the validity of these imperative arguments. Bernard Williams offers an argument that imperative inference is impossible: two imperatives will always have different permissive presuppositions, so a speaker will have to change his mind before uttering a second (...) imperative, and so imperatives cannot ever be accumulated into a set of premises. I offer four objections to Williams’ argument: (1) Permissive presuppositions are analogous to conversational implicature, and so should be ignored when formulating imperative arguments. (2) There are other valid argument forms, which Williams does not consider, that do not suffer from different permissive presuppositions. (3) There are explanations for the change in permissive presuppositions in Williams’ example other than a change of mind, so the different permissive presuppositions do not have to prevent accumulation. Finally, (4) Williams accepts enough logical relations between imperatives (contradiction and a form of negation) for a definition of a valid imperative inference to follow naturally. (shrink)

True beliefs and truth-preserving inferences are, in some sense, good beliefs and good inferences. When an inference is valid though, it is not merely truth-preserving, but truth-preserving in all cases. This motivates my question: I consider a Modus Ponens inference, and I ask what its validity in particular contributes to the explanation of why the inference is, in any sense, a good inference. I consider the question under three different definitions of ‘case’, and hence of ‘validity’: the orthodox definition given (...) in terms of interpretations or models, a metaphysical definition given in terms of possible worlds, and a substitutional definition defended by Quine. I argue that the orthodox notion is poorly suited to explain what's good about a Modus Ponens inference. I argue that there is something good that is explained by a certain kind of truth across possible worlds, but the explanation is not provided by metaphysical validity in particular; nothing of value is explained by truth across all possible worlds. Finally, I argue that the substitutional notion of validity allows us to correctly explain what is good about a valid inference. (shrink)

I object to Markos Valaris’s thesis that reasoning requires a belief that your conclusion follows from your premisses. My counter-examples highlight the important but neglected role of suppositional reasoning in the basis of so much of what we know.

In this paper, I explore a question about deductive reasoning: why am I in a position to immediately infer some deductive consequences of what I know, but not others? I show why the question cannot be answered in the most natural ways of answering it, in particular in Descartes’s way of answering it. I then go on to introduce a new approach to answering the question, an approach inspired by Hume’s view of inductive reasoning.

Consider: -/- The Evidence Question: When, and under what conditions does an agent have proposition E as evidence (at t)? -/- Timothy Williamson's (2000) answer to this question is the well-known E = K thesis: -/- E = K: E is a member of S's evidence set at t iff S knows E at t. -/- I will argue that this answer is inconsistent with the version of Bayesianism that Williamson advocates. This is because E = K allows an agent (...) to garner evidence via inductive inference whereas standard Bayesian views disallow such a thing. Since Williamson's version of Bayesianism shares the key features with the standard Bayesian view, there is an inconsistency. (shrink)

In this paper, we develop an account of the justification thinkers have for employing certain basic belief-forming methods. The guiding idea is inspired by Reichenbach's work on induction. There are certain projects in which thinkers are rationally required to engage. Thinkers are epistemically justified in employing any belief-forming method such that "if it doesn't work, nothing will" for successfully engaging in such a project. We present a detailed account based on this intuitive thought and address objections to it. We conclude (...) by commenting on the implications that our account may have for other important epistemological issues and debates. (shrink)

We examine the role of working memory's central executive in the mental model explanation of propositional reasoning by using two working memory measures: the classical “reading span” test by Daneman and Carpenter (1980) and a new measure. This new “reasoning span” measure requires individuals to solve very simple anaphora problems, and store and remember the word solution in a growing series of inferential problems. We present one experiment in which we check the involvement of the central executive in conditional and (...) disjunctive inference tasks and compare predictions of the new reasoning span test with those of the classical reading span test. The results of the experiment confirm that reasoning responses, which according to mental model theory require high cognitive work, are predicted by working memory measures. Results also show that some reasoning responses are probably obtained by means of superficial biases or strategies that do not load working memory. The reasoning span test, which involves the central executive to a greater degree, predicts reasoning performance better than the reading span test. The significance and possibilities of the new measure in studying reasoning are discussed. (shrink)

I pursue an answer to the psychological question “what is it for S to presuppose that p?” I will not attempt a general answer. Rather, I will explore a particular kind of presuppositions that are constituted by the mental act of reasoning: Inferential presuppositions. Indeed, I will consider a specific kind of inferential presuppositions—one that is constituted by a specific reasoning competence: The univocality competence. Roughly, this is the competence that reliably governs the univocal thought-components’ operation as univocal in a (...) line of reasoning. I will argue that the exercise of this reasoning competence constitutes certain inferential presuppositions. More specifically, I outline a conception of an inferential presupposition as a non-attitudinal but genuinely psychological and rationally committing relation that holds between a reasoner and a proposition. Thus, inferential presuppositions may be distinguished from tacit or standing attitudes that function as premise-beliefs in reasoning. Likewise inferential presuppositions may be distinguished from other kinds of presuppositions. In conclusion, I note some features of inferential presuppositions that bear on the epistemology of inference. (shrink)

The paper considers contemporary models of presumption in terms of their ability to contribute to a working theory of presumption for argumentation. Beginning with the Whatelian model, we consider its contemporary developments and alternatives, as proposed by Sidgwick, Kauffeld, Cronkhite, Rescher, Walton, Freeman, Ullmann-Margalit, and Hansen. Based on these accounts, we present a picture of presumptions characterized by their nature, function, foundation and force. On our account, presumption is a modal status that is attached to a claim and has the (...) effect of shifting, in a dialogue, a burden of proof set at a local level. Presumptions can be analysed and evaluated inferentially as components of rule-based structures. Presumptions are defeasible, and the force of a presumption is a function of its normative foundation. This picture seeks to provide a framework to guide the development of specific theories of presumption. (shrink)

I Imperative Sentences It has often been taken for granted by logicians that there is a class of sentences which is the proper subject-matter of logic, ...

Change in View offers an entirely original approach to the philosophical study of reasoning by identifying principles of reasoning with principles for revising one's beliefs and intentions and not with principles of logic. This crucial observation leads to a number of important and interesting consequences that impinge on psychology and artificial intelligence as well as on various branches of philosophy, from epistemology to ethics and action theory. Gilbert Harman is Professor of Philosophy at Princeton University. A Bradford Book.

The new paradigm in the psychology of reasoning draws on Bayesian formal frameworks, and some advocates of the new paradigm think of these formal frameworks as providing a computational-level theory of rational human inference. I argue that Bayesian theories should not be seen as providing a computational-level theory of rational human inference, where by “Bayesian theories” I mean theories that claim that all rational credal states are probabilistically coherent and that rational adjustments of degrees of belief in the light of (...) new evidence must be in accordance with some sort of conditionalization. The problems with the view I am criticizing can best be seen when we look at chains of inferences, rather than single-step inferences. Chains of inferences have been neglected almost entirely within the new paradigm. (shrink)

Some philosophers have recently argued that there are no diachronic norms of epistemic rationality, that is, that there are no norms regarding how you should change your attitudes over time. I argue that this is wrong on the grounds that there are norms governing reasoning.

I argue that the accounts of inference recently presented (in this journal) by Paul Boghossian, John Broome, and Crispin Wright are unsatisfactory. I proceed in two steps: First, in Sects. 1 and 2, I argue that we should not accept what Boghossian calls the “Taking Condition on inference” as a condition of adequacy for accounts of inference. I present a different condition of adequacy and argue that it is superior to the one offered by Boghossian. More precisely, I point out (...) that there is an analog of Moore’s Paradox for inference; and I suggest that explaining this phenomenon is a condition of adequacy for accounts of inference. Boghossian’s Taking Condition derives its plausibility from the fact that it apparently explains the analog of Moore’s Paradox. Second, in Sect. 3, I show that neither Boghossian’s, nor Broome’s, nor Wright’s account of inference meets my condition of adequacy. I distinguish two kinds of mistake one is likely to make if one does not focus on my condition of adequacy; and I argue that all three—Boghossian, Broome, and Wright—make at least one of these mistakes. (shrink)

An enkratic agent is someone who intends to do A because she believes she should do A. Being enkratic is usually understood as something rationality requires of you. However, we must distinguish between different conceptions of enkratic rationality. According to a fairly common view, enkratic rationality is solely a normative requirement on agency: it tells us how agents should think and act. However, I shall argue that this normativist conception of enkratic rationality faces serious difficulties: it makes it a mystery (...) how an agent's thinking and acting can be guided by the enkratic requirement, which, as I shall further argue, is something that an adequate conception of enkratic rationality must be able to explain. This, I suggest, motivates exploring a different account of enkratic rationality. On this view, enkratic rationality is primarily a constitutive requirement on agency: it is a standard internal to agency, i.e., a standard that partly spells out what it is to exercise one's agential powers well. (shrink)

Richard Fumerton’s “Principle of Inferential Justification” holds that, in order to be justified in believing P on the basis of E, one must be justified in believing that E makes P probable. I argue that the plausibility of this principle rests upon two kinds of mistakes: first, a level confusion; and second, a fallacy of misconditionalisation. Furthermore, Fumerton’s principle leads to skepticism about inferential justification, for which reason it should be rejected. Instead, the examples Fumerton uses to motivate his principle (...) can be accounted for using a different principle: in order for S to be justified in believing P on the basis of E, it must be true that E makes P probable. The latter principle can be independently motivated and does not lead to skepticism. (shrink)

The primary purpose of the paper is to present the issue of extrapolation, which is interesting from the perspective of contemporary philosophy of science. For its proper explanation, it is crucial to distinguish it from terms of similar meaning, such as analogy, induction or statistical inference. The second goal is to indicate key differences that exist between extrapolative inference and analogical reasoning. Because of this the ascertaining of the identification of these concepts would be a mistake though, of course, there (...) is no way not to notice certain similarities. (shrink)

This paper critically examines currently influential transparency accounts of our knowledge of our own beliefs that say that self-ascriptions of belief typically are arrived at by “looking outward” onto the world. For example, one version of the transparency account says that one self-ascribes beliefs via an inference from a premise to the conclusion that one believes that premise. This rule of inference reliably yields accurate self-ascriptions because you cannot infer a conclusion from a premise without believing the premise, and so (...) you cannot infer from a premise that you believe the premise unless you do believe it. I argue that this procedure cannot be a source of justification, however, because one can be justified in inferring from p that q only if p amounts to strong evidence that q is true. This is incompatible with the transparency account because p often is not very strong evidence that you believe that p. For example, unless you are a weather expert, the fact that it will rain is not very strong evidence that you believe it will rain. After showing how this intuitive problem can be made precise, I conclude with a broader lesson about the nature of inferential justification: that beliefs, when justified, must be underwritten by beliefs, when justified, must be underwritten by evidential relationships between the facts or propositions which those beliefs represent. (shrink)

An influential view in the epistemology of testimony is that typical or paradigmatic beliefs formed through testimonial uptake are noninferential. Some epistemologists in particular defend a causal version of this view: that beliefs formed from testimony (BFT) are generated by noninferential processes. This view is implausible, however. It tends to be elaborated in terms that do not really bear it out – e.g. that BFT is fixed directly, immediately, unconsciously or automatically. Nor is causal noninferentialism regarding BFT plausibly expressed in (...) terms of belief-independent belief formation; the complex cognitive details of BFT fixation do not accord well with such a view. But perhaps the most significant issue is that the relevant causal notion of inference itself is not particularly well-defined, at least with respect to BFT. Causal noninferentialism in this domain is obscure as a result, but this does not in turn clearly vindicate any interesting version of inferentialism. (shrink)