'The inner touch: Archaeology of a sensation.' Daniel Heller-Roazen. MIT Press. 2007.

Down the ages, great minds have explored the idea that sentient life incorporates a distinctive and elusive feature – a feature that cannot be wholly captured in terms of the qualitative character associated with what the individual senses are designed to track when performing their offices in enabling creatures to navigate the external world. From Aristotle onwards, rich attention has been paid to this alleged sense (or feeling) of living, of existing, or of one’s lived body and so on. The feeling in question purportedly is that which attends all unimpaired sentient activity (and possibly even its absence) – it has been thought of as a kind of animal feeling, that can disrupted or made more manifest by certain psychological and medical disorders. Amongst the many diverse attempts to formulate and understand the nature of this special kind of sentience, it has been variously equated with certain functions assigned to the Aristotelian common sense, a central or master faculty that presides over and unifies the perceptual activity, a kind of inner touch or sensitivity, and as a form of apperception (distinct from explicit consciousness). The twenty-five elegantly written chapters of Heller-Roazen’s book treat the reader to beautifully framed insights into the way ancient, medieval, Arabic and modern philosophers addressed this topic.