Online research in philosophy

Knowledge Representation and Reasoning (KR&R) is based on the idea that propositional content can be rigorously represented in formal languages long the province of logic, in such a way that these representations can be productively reasoned over by humans and machines; and that this reasoning can be used to produce knowledge-based systems (KBSs). As such, KR&R is a discipline conventionally regarded to range across parts of artificial intelligence (AI), computer science, and especially logic. This standard view of KR&R’s participating fields is correct — but dangerously incomplete. The view is incomplete because, as we explain herein, sophisticated KR&R must rely heavily upon philosophy. Encapsulated, the reason is actually quite straightforward: Sophisticated KR&R must include the representation of not only simple properties, but also concepts that are routine in the formal sciences (theoretical computer science, mathematics, logic, game theory, etc.), and everyday socio-cognitive concepts like mendacity, deception, betrayal, and evil. Because in KR&R the representation of such concepts must be rigorous in order to enable machine reasoning (e.g., machine-generated and machine-checked proofs that a is lying to b) over them, philosophy, devoted as it is in no small part to supplying analyses of such concepts, is a crucial partner in the overall enterprise. To put the point another way: When the knowledge to be represented is such as to require lengthy formulas in expressive formal languages for that representation, philosophy must be involved in the game. In addition, insofar as the advance of KR&R must allow formalisms and processes for representing and reasoning over visual propositional content, philosophy will be a key contributor into the future.

From its beginnings in Aristotle, logic was intended to account not only for reasoning that is theoretical (or conclusion-oriented), but for reasoning that is practical (or actionoriented). However, despite an interest in the topic that continues to the present, the practical side of reasoning has remained broadly speculative. At least in some domains (mathematics, in particular), there are well developed proof-theoretic and semantic theories that yield quite detailed models of correct reasoning, and these models are useful for both theoretical and practical purposes. In contrast, the logical work on practical reasoning has remained broadly speculative and disengaged from applications. Logical formalisms have not been forthcoming that would be useful either in designing an agent that needs to act intelligently, or in helping an intelligent agent to evaluate its reasoning about action.

The view to be defended in this paper is intended to be a novel and compelling model of instrumental practical reasoning, reasoning aimed at determining how to act in order to achieve a given end in a certain set of circumstances. On standard views of instrumental reasoning, the end in question is the object of a particular desire that the agent has, a desire which, when combined with the agent’s beliefs about what means are available to him or her in order to satisfy that desire, can cause the formation of an independent desire or intention to engage in the relevant means. One of the main goals in what follows is to show that such views provide an inadequate understanding of instrumental practical reasoning when it comes to the practical lives of agents.

This paper addresses an argument offered by John Hawthorne gainst the propriety of an agent’s using propositions she does not know as premises in practical reasoning. I will argue that there are a number of potential structural confounds in Hawthorne’s use of his main example, a case of practical reasoning about a lottery. By drawing these confounds out more explicitly, we can get a better sense of how to make appropriate use of such examples in theorizing about norms, knowledge, and practical reasoning. I will conclude by suggesting a prescription for properly using lottery propositions to do the sort of work that Hawthorne wants from them.

I am currently examining the suggestion that assertion and practical reasoning are subject to specifically epistemic norms, and the consequences of this suggestion for the correct account of knowledge. One currently popular view is that knowledge is the epistemic norm of both assertion and practical reasoning (see DeRose, Hawthorne, Stanley and Williamson). If assertion and practical reasoning are governed by the knowledge norm, then one criterion for an account of knowledge is that it should respect the ties between knowledge, assertion and practical reasoning. In this way, the knowledge norm is at the heart of contemporary debate about the correct account of knowledge, e.g. the debate between contextualism and invariantism (see Hawthorne.

To be able to say what practical reasoning is, we first need to say what reasoning is and what the conclusion of a process of reasoning is. I shall do this in sections 1 and 2. We can then make a distinction between practical and theoretical reasoning. There are three main ways to do this, which I shall survey in sections 3 to 5. I shall end by suggesting that there are different kinds of practical reasoning.

This paper seeks a better understanding of the elements of practical reasoning: premises and conclusion. It argues that the premises of practical reasoning do not normally include statements such as ‘I want to ϕ’; that the reasoning in practical reasoning is the same as in theoretical reasoning and that what makes it practical is, first, that the point of the relevant reasoning is given by the goal that the reasoner seeks to realize by means of that reasoning and the subsequent action; second, that the premises of such reasoning show the goodness of the action to be undertaken; third, that the conclusions of such reasoning may be actions or decisions, that can be accompanied by expressions of intention, either in action, or for the future; and that these are justified, and might be contradicted, in ways that are not only peculiar to them (i.e. in ways that diverge from those found in theoretical reasoning), but are distinctively practical, in that they involve reference to reasons for acting and to expressions of intention, respectively.1.

Practical Reasoning and Ethical Decision presents an account of practical reasoning as a process that can explain action, connect reasoning with intention, ...

In Knowledge and Lotteries, Hawthorne argues for a view on which whether a speaker knows that p depends on whether her practical environment makes it appropriate for her to use p in practical reasoning. It may seem that this view yields a straightforward account of why knowledge is important, based on the role of knowledge in practical reasoning. I argue that this is not so; practical reasoning does not motivate us to care about knowledge in itself. At best, practical reasoning motivates us to care about several other concepts in themselves, and ascriptions of knowledge provide economical summaries of these independently important desiderata.

I argue that logical understanding is not propositional knowledgebut is rather a species of practical knowledge. I further arguethat given the best explanation of logical understanding someversion or another of inferential role semantics must be the correct account of the determinants of logical content.