The research literature on causal attribution and social cognition generally consists of many fascinating but fragmented and superficial phenomena. These can only be understood as an organised whole by elucidating the fundamental psychological assumptions on which they depend. Psychological Metaphysics is an exploration of the most basic and important assumptions in the psychological construction of reality, with the aim of showing what they are, how they originate, and what they are there for. Peter White proposes that people basically understand causation in terms of stable, special powers of things operating to produce effects under suitable conditions. This underpins an analysis of people's understanding of causal processes in the physical world, and of human action. In making a radical break with the Heiderian tradition, Psychological Metaphysics suggests that causal attribution is in the service of the person's practical concerns and any interest in accuracy or understanding is subservient to this. Indeed, a notion of regularity in the world is of no more than minor importance, and social cognition is not a matter of cognitive mechanisms or processes but of cultural ways of thinking imposed upon tacit, unquestioned, universal assumptions.