This paper outlines an account of conditionals, the evidential account, which rests on the idea that a conditional is true just in case its antecedent supports its consequent. As we will show, the evidential account exhibits some distinctive logical features that deserve careful consideration. On the one hand, it departs from the material reading of ‘if then’ exactly in the way we would like it to depart from that reading. On the other, it significantly differs from the non-material accounts which hinge on the Ramsey Test, advocated by Adams, Stalnaker, Lewis, and others.

This paper outlines an account of concessive conditionals that rests on two main ideas. One is that the logical form of a sentence as used in a given context is determined by the content expressed by the sentence in that context. The other is that a coherent distinction can be drawn between a reading of 'if' according to which a conditional is true when its consequent holds on the supposition that its antecedent holds, and a stronger reading according to which a conditional is true when its antecedent supports its consequent. As we will suggest, the logical form of concessive conditionals can be elucidated by relying on this distinction.

This paper investigates the logic of Ockhamism, a view according to which future contingents are either true or false. Several attempts have been made to give rigorous shape to this view by defining a suitable formal semantics, but arguably none of them is fully satisfactory. The paper draws attention to some problems that beset such attempts, and suggests that these problems are different symptoms of the same initial confusion, in that they stem from the unjustified assumption that the actual course of events must be represented in the semantics as a distinguished history, the Thin Red Line.

This paper explores an idea of Stoic descent that is largely neglected nowadays, the idea that an argument is valid when the conditional formed by the conjunction of its premises as antecedent and its conclusion as consequent is true. As will be argued, once some basic features of our naïve understanding of validity are properly spelled out, and a suitable account of conditionals is adopted, the equivalence between valid arguments and true conditionals makes perfect sense. The account of validity outlined here, which displays one coherent way to articulate the Stoic intuition, accords with standard formal treatments of deductive validity and encompasses an independently grounded characterization of inductive validity.

conditional' abbreviates 'indicative conditional'. This is not intended to suggest that counterfactuals differ in some important respect. On the contrary, most of what will be said about conditionals can be extended, mutatis mutandis, to counterfactuals. But for the sake of simplicity we will not deal with such extension.According to connexiviststhe advocates of connexive logic -AT, AT ′ , BT, BT ′ are highly plausible, so a good theory of conditionals should validate them. The intuitive character of AT, AT ′ , BT, BT ′ is thus regarded as a main motivation, if not the main motivation, for adopting connexive logic. 1 Some connexivists have suggested that the truth conditions of p>q are to be given in terms of a relation between p and q, some sort of incompatibility that is not reducible to the impossibility that p and q are true. For example, Nelson has defined such a relation, and Angell has incorporated it into a logical system. A theory of conditionals along these lines validates AT, AT ′ , BT, BT ′ (Nelson 1930; Angell 1962).Nelson's definition is not the only option. In fact it is not even obvious that we need some non-standard notion of incompatibility in order to validate AT, AT ′ , BT, BT ′ . It is reasonable to expect that a definition based on entirely different notions can lead to the same result. So, we will simply call 'connexivist' any theory of conditionals that validates AT, AT ′ , BT, BT ′ , and we will not deal with the differences between the various connexivist theories. 2 This paper is about the intuitive basis of connexive logic, so the question it addresses is whether AT, AT ′ , BT, BT ′ should be treated as theorems in virtue of their intuitive content. The answer it suggests is that there is no reason to think they should: although the core idea behind AT, AT ′ , BT, BT ′ is essentially sound, it is far from obvious that AT, AT ′ , BT, BT ′ hold unrestrictedly.Note that here the qualification 'in virtue of their intuitive content' is crucial, for there may be independent reasons for treating AT, AT ′ , BT, BT ′ as theorems. A system of connexive logic, just as any formal apparatus, may be motivated in many different ways, and this paper focuses only on one of them. Aristotle's thesisAs we have seen, connexivists think that AT and AT ′ as highly plausible, so that a good theory of conditionals should validate them. What will be suggested