A certain order or stability of nature has often been seen as a necessary presupposition of many of our scientific practices, in particular of our use of information gained in one kind of circumstance to explain or predict what happens in quite different situations. John Maynard Keynes and, more recently, Nancy Cartwright have argued that these practices commit us to the existence of stable ‘atoms’ or ‘natures’ or ‘tendencies.’ The phenomena we observe in nature are, on this view, the result of superimposing the invariable, context-independent effects of all the different tendencies involved.

The validity of argument by disjunctive syllogism (henceforth, DS) has been denied by proponents of relevant and paraconsistent logic (who are sometimes one and the same). DS is stigmatised for its role in inferences — most notably C.I. Lewis's derivation of that fallacy of irrelevance ex falso quodlibet (EFQ) — that involve both it and other rules of inference governing disjunction, or, to speak more precisely, other rules of inference taken to apply to the very same disjunction that obeys DS. In avoiding these inferences the road less travelled is to deny the identity rather than to deny DS: what follows is, then, an exercise in disjoining disjunctions.

Game theorists assume that rational defensibility is a necessary condition for moral, social, or political justification. By itself, this is a fairly uncontroversial claim; most moral or political philosophers would agree. And yet game theorists tend to be advocates of the free market. External critics of game theory usually claim this is because game theorists assume that individuals are atomistic and self-interested. Game theorists themselves deny this, however, for what strike us as good reasons. In principle, game theory has no necessary ties to right-wing distribution schemes. Why, then, is game theory almost exclusively the province of conservative philosophers, political scientists, and economists? The problem, we believe, lies in the theory of rational choice standardly employed by game theory. Even if we accept, for the purposes of argument, game theory's account of the justification of moral dispositions — that a disposition is morally justified if and only if, in its absence, it would be game theoretically rational to acquire it — we need not be led to right-wing solutions. If we expand the kinds of choices facing individuals to include choices about what we will call ‘institutional roles,’ then we can explain the game theoretic rationality of the kinds of emotions and behavior exemplified by duty, loyalty, and love.

Une question très discutée chez les interprètes de Wittgenstein est celle de savoir comment comprendre le paradoxe au sujet des règles dont il parle dans le paragraphe 201 des Recherches philosophiques. Ilécrit: ‘Notre paradoxe était le suivant: une règle ne pourrait déterminer aucune conduite parce que n'importe quelle conduite pourrait être mise en accord avec la règle’ (PU § 201). Un peu plus haut, il faisait dire à son interlocuteur: ‘“Mais comment une règle peut-elle m'apprendre ce que je dois faire en ce point? Peu importe ce que je fais, cela pourra s’ accorder suivant une interprétation ou une autre avec la règle “’ (PU § 198).