During the past half-century, there has been intensive and often highly productive inquiry into human cognitive faculties, their nature and the ways they enter into action and interpretation. Commonly it adopts the thesis that “things mental, indeed minds, are emergent properties of brains,” while recognizing that “those emergences are … produced by principles that control the interactions between lower level events – principles we do not yet understand” (Mountcastle 1998: 1). The word “yet” expresses the optimism that has, rightly or wrongly, been a persistent theme throughout the period.

The thesis revives eighteenth-century proposals that were put forth for quite compelling reasons: in particular, the conclusion that Newton appeared to have established, to his considerable dismay, that “a purely materialistic or mechanistic physics” is “impossible” (Koyré 1957: 210); and the implications of “Locke's suggestion” that God might have chosen to “superadd to matter a faculty of thinking” just as he “annexed effects to motion which we can in no way conceive motion able to produce” (Locke 1975: 541, Book IV, Chapter 3, Section 6). The precedents of the early modern period, and the thinking that lay behind them, merit closer attention than they have generally, in my opinion, received. It is also worth remembering that lack of understanding of “mind/brain interaction” is not the only respect in which progress has been limited since the origin of the modern scientific revolutions.