In this essay, we will try to provide a formal analysis of practical inference, attentive to the various phases in which it is articulated, and being so capable of explaining both the logical conclusiveness of the inference and the probabilistic nature of its conclusion. An innovative purpose of this article is to show how the final deliberation leading to action—the ultimate practical judgment—takes place according to a logic consistent with the use of Bayes’ theorem. This is (...) why we refer to Bayesian practical inference in the title of this essay. (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, ...

The efficacy criterion of the FPL model wrongly takes the goals of practical inference to be uncontroversial. The robustness criterion is arbitrary; the accommodation criterion is too weak to differentiate between arch rival theories. All three criteria of FPL fail to address the relation between background philosophical theories and other elements of an inferential system.

In Intention, Anscombe says that practical reasoning is practical, not by virtue of its content, but rather by virtue of its form. But in her later essay ‘Practical Inference’, she seems to take this back, claiming instead that (1) the practicality of practical reasoning (or inference) resides in the distinctive use it makes of the premises, and (2) ‘it is a matter of indifference’ whether we say that it exemplifies a distinctive form. I aim (...) to show that Anscombe is right about (1) but wrong about (2): the distinctive use (or teleology) of practical reasoning explains its distinctive formal features, and when the former is thought through, the latter are revealed to be more numerous and significant than Anscombe seems to recognize. (shrink)

IN THIS paper, following Von Wright, I shall understand practical inferences to be concerned mainly with actions used as means to attain ends. Philosophers from Aristotle to Anscombe and Von Wright have regarded the notion of practical reasoning as crucial from the point of view of understanding rational action and it might further be argued that it is by reference to inductive—theoretical reasoning and practical reasoning that the limits of human rationality are defined; rationality, that is, might (...) be viewed as progress from basic propositions to basic actions. Proceeding from what appears to be a rather austere view of logic, Harman has denied the possibility of either an inductive or a practical logic which leads me to suspect that he would also take a dim view of the notion of "practical inference." Taking what is perhaps a more permissive view, however, and leaving aside problems raised by the notion of an "inductive" logic, I shall follow Kenny, Von Wright, and others in regarding practical inferences as legitimate topics for logical investigation. Whatever may be said in defence of Harman’s views on logic though, I am persuaded that he is mistaken when he writes. (shrink)

This is one of four volumes from the same press collecting Hare’s major papers. Of the six papers in this volume, two have appeared in Mind, one in the Philosophical Review, two have appeared in special collections, and only one has not been previously published. There is brief additional material appended to some of the articles and, perhaps most important, a four page bibliography of Hare’s writings. From this bibliography one can discover which of Hare’s articles appear in each of (...) the volumes of this group and also find their original location. One might thus save the cost of a volume or two for there is little doubt, considering the size and price of these books, upon what principle the publisher of this series has decided. The articles are largely a development and defense of Hare’s views of practical reason as set forth in The Language of Morals, with particular attention to the logical forms of imperatives and ought statements, and to the forms of inference valid for each. Beyond this basic theme, the collection is not particularly unified. Two fundamental impressions, however, emerge. The first is an awareness of the enormous influence of J. L. Austin on Hare’s thinking. This is evident not only in his discussion and rejection of Austin’s distinction between locutionary and illocutionary acts, but more importantly in his constant respect for ordinary usage and his resistance to ideal formalism. The second impression is that there is much to be done to develop a logic for imperative and prescriptive inferences. These papers present some basic principles for such a development but, since they are primarily defenses against criticisms of Hare’s book, there is an ad hoc character about them. What is now required is a more complete and systematic treatment of these topics. Ordinary language analysts might here make some inroads on the domain of formal logic to recall some of that logic to philosophy. The articles collected, therefore, are valuable, particularly as they encourage further development of the overlap of logic and ethics.—K. M. (shrink)

According to C. S. Peirce, abduction is a rational attempt to locate an explanation for a puzzling phenomenon, where this is a process that includes both generating explanatory hypotheses and selecting certain hypotheses for further scrutiny. Since inference is a controlled process that can be subjected to normative standards, essential to his view of abductive rasoning is that it is correlated to a unique species of correctness that cannot be reduced to deductive validity or inductive strength. This irreducibility claim (...) is of considerable importance for the logical and epistemological scrutiny of scientific methods, but it is not clear that Peirce produced a convicing argument for it. To the contrary, when the full structure of abductive argumentation is clarified, especially as presented in Peirce’s later writings on the topic, a good case can be made for viewing every inferential step in the abductive process as dissolving into familiar forms of deductive and inductive reasoning. Specifically, hypothesis-selection is a special type of practical inference that, if correct, is deductively valid, while the creative phase, hypothesis-generation, is not inferential at all. Once this is understood, it emerges that the familiar descriptions of abduction as “inference to the best explanation” or as a process of “belief revision” are, at best, misleading. (shrink)

I wish to examine a rather different way of thinking about permissibility, one according to which, roughly speaking, an agent acts impermissibly if and only if he acts for reasons insufficient to justify him in doing what he does. For reasons that will emerge in Section II, I call this the inferential account of permissibility. I shall not here try to prove that this account is superior to its rivals. My aims are more modest. I shall develop the inferential account, (...) exhibiting some of its attractions along the way, and then show that it is invulnerable to a number of influential objections to the very idea that an agent's reasons for acting could be directly relevant to whether he acts permissibly. If these objections have seemed decisive, it is because we have not considered the full range of possible accounts. The inferential account of permissibility is both plausible and attractive---it deserves to be taken seriously. (shrink)

The paper considers the general question of whether unconscious practical inference is possible. It undertakes an investigation of Freud's theory of psychoanalysis, in order to determine whether his theory can meet the requirements of the practical inference model, and thus make room for unconscious practical inference. The paper argues that it cannot: although Freud's theory appears to meet certain conditions necessary for practical inference, i.e., minimal agent rationality and the postulation of desires, (...) it leaves out one element which is essential for the identification of an unconscious practical inference—namely, unconscious belief. (shrink)

Different questions generate different forms of practical reasoning. A contextually unrestricted ‘What shall I do?’ is too open to focus reflection. More determinately, an agent may ask, ‘Shall I do X, or Y?’ To answer that, he may need to weigh things up—as fits the derivation of ‘deliberation’ fromlibra(Latin for ‘scales’). Ubiquitous and indispensable though this is, I mention it only to salute it in passing. Or he may ask how to achieve a proposed end: if his end is (...) to do X, he may ask ‘How shall I do X?’ Or he may ask how to apply a universal rule or particular maxim. Aristotle supplies examples inDe Motu Animalium(7.701a7 ff.), whose wording I freely adapt to my own purposes:A1 reasons to a necessary means to achieving an end:I will make a cloak.To make a cloak I must do A.So, I will do A. (shrink)

This article discusses how inference to the best explanation can be justified as a practical meta - argument. It is, firstly, justified as a practical argument insofar as accepting the best explanation as true can be shown to further a specific aim. And because this aim is a discursive one which proponents can rationally pursue in — and relative to — a complex controversy, namely maximising the robustness of one’s position, IBE can be conceived, secondly, as a (...) meta - argument. My analysis thus bears a certain analogy to Sellars ’ well - known justification of inductive reasoning ; it is based on recently developed theories of complex argumentation. (shrink)

Students face many important decisions: What college or university should I attend? What should I study? What kind of job should I try to get? Which people should I hang out with? Should I continue or break off a relationship? Should I get married? Should I have a baby? What kind of medical treatment should I use? A theory of practical reasoning should have something to say about how students and other people can improve their decision making.

Harman and Kulkarni provide a rigorous and informative discussion of reliable reasoning, drawing philosophical conclusions from the elegant formal results of statistical learning theory. They have presented a strong case that statistical learning theory is highly relevant to issues in philosophy and psychology concerning inductive inferences. Although I agree with their general thrust, I want to take issue with some of the philosophical and psychological conclusions they reach. I will first discuss the general problem of assessing norms and propose a (...) metanormative decision procedure that can then be applied to the assessment of inductive methods. In particular, I will apply it to the assessment of the method of inference that Harman and Kulkarni call transduction. (shrink)

Some arguments include imperative clauses. For example: ‘Buy me a drink; you can’t buy me that drink unless you go to the bar; so, go to the bar!’ How should we build a logic that predicts which of these arguments are good? Because imperatives aren’t truth apt and so don’t stand in relations of truth preservation, this technical question gives rise to a foundational one: What would be the subject matter of this logic? I argue that declaratives are used to (...) produce beliefs, imperatives are used to produce intentions, and beliefs and intentions are subject to rational requirements. An argument will strike us as valid when anyone whose mental state satisfies the premises is rationally required to satisfy the conclusion. For example, the above argument reflects the principle that it is irrational not to intend what one takes to be the necessary means to one’s intended ends. I argue that all intuitively good patterns of imperative inference can be explained using off-the-shelf formulations of our rational requirements. I then develop a formal-semantic theory embodying this view that predicts a range of data, including free-choice effects and Ross’s paradox. The resulting theory shows one way that our aspirations to rational agency can be discerned in the patterns of our speech, and is a case study in how the philosophy of language and the philosophy of action can be mutually illuminating. (shrink)

Reichenbach held that all scientific inference reduces, via probability calculus, to induction, and he held that induction can be justified. He sees scientific knowledge in a practical context and insists that any rational assessment of actions requires a justification of induction. Gaps remain in his justifying argument; for we can not hope to prove that induction will succeed if success is possible. However, there are good prospects for completing a justification of essentially the kind he sought by showing (...) that while induction may succeed, no alternative is a rational way of trying.Reichenbach's claim that probability calculus, especially via Bayes' Theorem, can help to exhibit the structure of inference to theories is a valuable insight. However, his thesis that the weighting of all hypotheses rests only on frequency data is too restrictive, especially given his scientific realism. Other empirical factors are relevant. Any satisfactory account of scientific inference must be deeply indebted to Reichenbach's foundation work. (shrink)