In this chapter we cover a series of questions about explanations that are relevant to understanding philosophical issues in psychopharmacology. We have already begun to develop a particular contrast in philosophical discussion of explanations – the classical vs. critical approaches. The classical approach takes the view that it is possible to generate systematic generalizations or covering laws that describe the facts of the world (e.g. of the brain), and their relationships. The critical approach argues that human phenomena require a different kind of knowledge, one that is based on subjective understanding (e.g. of agents and their minds). The synthetic position taken here says that our brain-minds engage in various kinds of activity – both physical and social – are able to develop maps which provide explanations of the natural and human world, and can reasonably (cognitive-affectively) debate these maps and attempt to come up with ones that have greater explanatory power. Such explanatory power lies in understanding structures and their mechanisms (Bhaskar, 1978) and functions (Bolton & Hill, 1996).

In the next section this schema is used to discuss in turn how pharmacotherapy and psychotherapy work (which entails some discussion of brain-mind and nature–nurture relations), how placebo and nocebo effects occur (which leads to some discussion of symbolic grounding, and of the unconscious), and how evolutionary theory impacts on our understanding of cognitive-affective processes including those involved in the response to psychotropics and substances (which then involves some discussion of the constructs of function and dysfunction).