Mental Acts, Externalism and Fiat Objects: An Ockhamist Solution

To consider whether nature carves itself, this chapter illustrates how, on William of Ockham’s mature account of mental acts, the formation of a judgement, for instance that this wall is white, involves the combination of two intuitions of singular objects, namely ‘this wall’ and ‘this white’, that are presented to us by way of a causal interaction. But talk of ‘causal interactions’ seems merely to name the problem of how we can ensure that the segments and features of the world that impinge on our senses correspond to the way things really divide up rather than merely to the ways that habit and convenience dictate. Fedriga's underlying aim is to bring out the relevance of the Ockhamist position for contemporary forms of anti-foundationalism, and specifically those that are diffident of there being such a thing as ‘the way things really divide up’. Yet, even if there is an irreducible plurality of ways in which we can divide things up, there remains some sense in which the causal efficacy of the segments and features of the world that figure in our judgements involve the meeting of the organized matter of the wall and its reflectance with the organized matter of our perceptual apparatus.