In her 1938 paper ‘Logical and Metaphysical Necessity’, Martha Kneale introduces the necessary a posteriori. I present a critical summary of Kneale's argument that so-called ‘metaphysical propositions’ are necessary but not a priori. I argue that Kneale is well placed to offer a template for reconciling conceivability approaches to modal epistemology with the post-Kripkean trend for taking metaphysical necessities to have their source in mind-independent reality.

Recently, a debate has developed between those who claim that essence can be explained in terms of de re modality (modalists), and those who claim that de re modality can be explained in terms of essence (essentialists). The aim of this paper is to suggest that we should reassess. It is assumed that either necessity is to be accounted for in terms of essence, or that essence is to be accounted for in terms of necessity. I will argue that we should assume neither. I discuss what role these key notions – essence and necessity – can reasonably be thought to contribute to our understanding of the world, and argue that, given these roles, there is no good reason to think that we should give an account of one in terms of the other. I conclude: if we can adequately explain de re modality and essence at all, we should aim to do so separately.

One striking contrast that Kant draws between the kind of cognitive capacities that humans have and alternative kinds of intellect concerns modal concepts. Whilst ‘it is absolutely necessary for the human understanding to distinguish between the possibility and the actuality of things’ (5: 401), the very distinction between possibility and actuality would not arise for an intuitive understanding. The aim of this paper is to explore in more detail how the functioning of these cognitive capacities relates to modal concepts, and to provide a model of the intuitive understanding, in order to draw some general lessons for our ability to make modal judgements, and the function of such judgements.