1997: The Is-Ought Problem

Survey talk delivered to the Cambridge Meta-Ethics group in 2011. After some brief remarks on the ambiguities in Hume's version of No-Ought-From-Is, I outline Prior's paradox and discuss the various responses, principally mine (the New Zealand Plan) and Schurz's (the Austrian Plan). In this text I add seven appendices drawn mainly from my introduction to Hume On Is and Ought, amplifying the argument, discussing matters arising and outlining rival approaches to the problem, principally the relevantist solution, due to Ed Mares, and the Inference Barrier solution (the Scottish/Australian Plan) due to Gillian Russell and Greg Restall. I also discuss the work of Stephen Maitzen and Mark Nelson. In this talk I emphasize the logical aspects of the issue. Drafts of my contributions to this debate available above in 'Papers'. 'The Triviality of Hume's Law', 'Coda: Truth and Consequences' and 'Subtance, Taxonomy, Content and Consequence' emphasize the logical and meta-ethical aspects of the the issue, whilst 'Letter From a Gentleman' and 'Snare's Puzzle/Hume's Purpose' emphasize meta-ethics and the historical Hume. 'Comments on "Hume's Master Argument"' deals with all three themes. The kick-off paper is 'Logic and the Autonomy of Ethics' (1989). The last in the sequence is 'Hume on is and Ought: Logic Promises and the Duke of Wellington'.

Australasian Journal of Philosophy, vol. 79. no. 4., pp 578-580., 2001

A review of Schurz's great work.

This paper dispels a misconception that has haunted western philosophy for nearly three hundred years, the idea that you cannot infer "ought" statements from "is" statements. In fact you can, quite easily. The “ought” is a hypothetical imperative, a prudential recommendation, not a categorical, universal, or moral imperative. But it is an “ought” nevertheless, and of great practical import.

Sanne Taekema, Bart van Klink and Wouter de Been (eds.), Facts and Norms in Law, Edward Elgar 2016, p. 23-49, 2016

Philosophical and methodological discussions with regard to normative and value judgment presuppose the availability of a set of clear concepts by means of which these discussions can be made fruitful. To provide such a framework, or at least its beginnings, the present paper makes and explains distinctions between, amongst others, facts and descriptions thereof, kinds of objectivity of facts, deontic facts and norms, kinds of deontic facts, kinds of rules, and facts and values. By means of some examples, the usefulness of the clear concepts for methodological issues is illustrated.

Logique et Analyse

2000

A logical investigation of the Is-Ought problem is in a subtle position with respect to the question of ethical cognitivism. It has to presuppose at certain portion of cognitivism, but it has to remain ignorant with respect to rest of it. Let me therefore start my talk with a differentiation in the concept of cognitivism. What a logical investigation of the Is-Ought problem has to assume is what I call (1.) Semantic Cognitivism: (a) Normative (ethical) assertions have semantical contents which can be represented as propositions, and (b) these propositions can be semantically evaluated by a meta-logical 'truth' or 'correctness' predicate.

Deontic Modality, 2016

This essay offers an account of the truth conditions of sentences involving deontic modals like 'ought', designed to capture the difference between objective and subjective kinds of 'ought' This account resembles the classical semantics for deontic logic: according to this account, these truths conditions involve a function from the world of evaluation to a domain of worlds (equivalent to a so-called "modal base"), and an ordering of the worlds in such domains; this ordering of the worlds itself arises from two further elementsa probability function and a value functionsince this ordering ranks the worlds in accordance with the expected value of certain propositions that are true at those worlds. Thus, a proposition of the form 'Ought (p)' is true at a world of evaluation w if and only if p is true at all the top-ranked worlds in the domain assigned to w. This domain of worlds consists of metaphysically possible worlds, while the probability function is defined over a space of epistemically possible worlds (which may include metaphysically impossible worlds, such as worlds where Hesperus is not Phosphorus). Evidence is given that this account assigns the correct truth conditions to a wide range of sentences involving 'ought'. Since these truth conditions involve both a domain of metaphysically possible worlds and a space of epistemically possible worlds, there are two corresponding kinds of conditional involving 'ought', depending on which space of worlds is restricted by the conditional. Finally, some objections that might be raised against this account are answered.

This essay investigates the possibility of analysingì ought to do a' asìt ought to be that i do a' in an axiological setting. Axiological conceptions of deontic logic dene what ought to be as that which is better than the alternative, and dene what an agent ought to do as that which has the best outcome. How one might determine thèbest outcome' is takes philosophical work. The formal semantics for ought-to-be interprets propositions as sets of states, and the outcomes of actions for ought-to-do are also interpreted as sets of states. Thus both terms require a relation which compares sets of states based on a fundamental (weak) betterness relation between states. In this paper the relationships between ve denitions of ought-to-do and one (traditional) denition of ought-to-be are considered in such an axiological setting. It is shown that on four of those denitions it is impossible to nd a relation on sets of states which allowsì ought to do a' to be analysed asìt ought to be that i do a'. One denition of ought-to-do does make the reduction possible, but it is argued that it is defective as an interpretation of ought-to-do. Connections with Horty's work on agency and deontic logic are also discussed.

Noûs, 1974

This paper is the beginning of an explication of the "normative-descriptive" or "ought-is" distinction by way of the notion that our knowledge of other minds is the result of our imposition of constraints on the interpretation of events as actions by agents. My hope is that a general theory of rationality and the normative can be derived from an examination of the constraints it is rational to impose on agent-interpretation, i.e., of the fundamental knowledge we have of persons as persons. My attempt at an explication of the "ought-is" distinction takes the following form: I want to find an absolutely general way of determining when "ought"-sentences are true. Since the extensions of the account given below to interesting cases of "ought"-sentences such as moral and prudential cases depend on relatively complicated constraints on agent-interpretation,l this paper will deal only with the simplest case of "ought"-sentences, the "logical ought". If logic is thought of as a normative science of belief, it yields one of the simplest cases of the "normative-descriptive" dichotomy. By the "logical ought" I understand what might be called consequences of the canons of obedience to the laws of thought. An instance of such an "ought" occurs in "If you believe that frogs are green, you ought to believe that anything that's not green is not a frog." The "logical ought" is, as it were, the minimal rational "ought", the one that prescribes closure of belief under logical consequence and proscribes inconsistency of belief. It should be pointed out that the principles of the "logical ought" often come into conflict with other canons of rationality, just as principles of moral "oughts" come into conflict with each other. The example above is surely true even if NOUS 8 (1974) ?) 1974 by Indiana University 233

Lafollette ed. The International Encyclopedia of Ethics, Oxford, Wiley-Blackwell. , 2013

Is/Ought survey article, presupposing a little more logical sophistication that the above paper for Philosophy Now. For the Academia version I have added footnotes referencing the papers in which I argue at length for my more contentious claims. For papers which expand on the historical Hume and the implications of No-Ought-From-Is for contemporary Meta-Ethics, see below 'Letter from a Gentleman' and 'Snare's Puzzle/Hume's Purpose'