In his first chapter, Sherrington discusses the sixteenth-century physician Jean Fernel’s understanding of nature as a ‘cause of the manifold of the perceptible world around us’, which when viewed as a created thing might give insight into its creator. What Sherrington seems to suggest is that as our understanding of the natural world grows and evolves, so too should our conceptions of natural theology which inform not only our understanding of God, but also our place in a created order. Sherrington, following from Fernel, argues that the nature of humans is not in what they are, but in what they can be or are in the process of becoming.

In the second chapter, ‘The Natural and Superstition’, Sherrington addresses the belief in astrology which dominated Fernal’s world. Although initially supportive of the ‘science’, Fernal gradually withdrew from it at a time when many viewed it as the ‘most wonderful chapter in the whole of science’. Why? Fernal perceived constancy in nature that did not depend on astral bodies dictating to the corporeal human bodies he studied as a physician. It seemed incompatible with his view of religion, philosophy and physiological function. Yet his rejection of the superstitious aspects of humankind’s concept of the natural world did not diminish the mystery of nature for him, nor remove the necessity for seeking out its mysteries.

The third chapter turns to Sherrington’s own biological expertise. ‘Life in Little’ focuses on cellular biology and in particular the ‘life’ that exists beyond the inherent attributes of matter. The animation of these cells, although it can be described in terms of electricity, remains a mystery. In the human body the culmination of these mysteries finds a new expression, in that millions of cells find a unity while keeping their multiplicity. At great length and detail the author focuses on the development of an embryo from a single cell into its mature human form. He suggests that the capacity of what it will be is contained in the cell, both for formation and function. He terms this the ‘Wisdom of the Body’ in chapter 4. Physics and chemistry can explain how these processes come about but not why or whence. They can affirm, in Sherrington’s words, that they are neither ‘accident nor miracle’. What remains, what continues to elude science, is an explanation. Sherrington’s fifth chapter, ‘Earth’s Reshuffling’, addresses the formation of the earth in its organic and inorganic forms. Though the formation of the earth’s crusts can be describe in terms of geophysics and the evolution of life can be defined as an ongoing process, the great question which arose in the previous chapter persists. Is the natural world in its laws and function to be interpreted as ‘mechanistic’ or ‘teleological’?

Sherrington argues in ‘A Whole Presupposed of Its Parts’ that organisms must be the sum of their parts and more. Whereas Fernel believed the body served as ‘a tenement’ for our faculties or a boat which the mind guides, and Descartes, coming under the influence of the French physician, held it to be ‘a mechanism actuating itself’, Sherrington states that bodies operate beyond mere reflex and the mind ‘makes an effective contribution to life’. He continues in the following chapters, ‘The Brain and Its Work’, ‘The Organ of Liaison’ and ‘Brain Collaborates with Psyche’, to discuss the physiology of the brain and neurological system in its relation to the body and other bodies. At home in his field, these three chapters express the rich complexity of the human brain in its physiology and function. Not only does the mind animate the body, it serves as our sole conduit for community and communication. The mind allows the ‘finite mind’ to communicate with other ‘finite minds’. Chapters 10 and 11, ‘The Earth’s Alchemy’ and ‘Two Ways of One Mind’, introduce the complexities of sensory nerves, the subconscious mind and its possible relationship to the soul. In discussing the relation between the mind and the soul, he quotes Aristotle’s De Anima: ‘to speak of the soul as feeling angry is no more appropriate than to speak of the soul as weaving or building. Perhaps, in fact, it is better to say not that the soul pities or learns or infers, but rather that the man does so through his soul’. Similarly, he speaks of the mind as being beyond the mere physiology of the brain. The mind ‘goes therefore in our spatial world more ghostly than a ghost . . . it is a thing not even of outline; it is not a “thing”.’

In the final chapter, ‘Altruism’, Sherrington makes a clear distinction between the natural sciences distancing themselves from all judgements regarding ‘good’, ‘bad’, ‘right’ or wrong, and the fundamental aspect of natural theology to find value, truth and conviction in a created order. They approach the world from two different ends. Science seeks to strip the world of emotion and feeling, divesting itself of the ‘anthropomorphic’, while the great religions ‘cultivate the Deity as a personal Deity’, thus bringing emotion and relationship into their worldview. Taking hold of David Hume’s question of whether ‘the pain of this world is offset by its joy’, he argues that this is not the point: nature is harmony. Both exist. He ends with a description of ‘natural religion’. Through scientific advancement humankind finds itself in a new place in the universal order, no longer dependent upon external intervention. He does not seek to explain why the world is the way that it is, but rather that it simply is, whether by mechanistic or teleological means. ‘Compared with a situation where the human mind beset with its complexities had higher mind and higher personality than itself to lean on and seek counsel from, this other situation where it has no appeal and nor resort for help beyond itself, has an element of tragedy and pathos’. Sherrington argues that, put in a place where humanity does not have superstitious concepts of the universe underpinning its moral actions, it will ‘elevate’ its ‘spirit to the position of a protagonist of virility and dignity which otherwise the human figure could not possess’. This leaves humanity with ultimate responsibility, recognition of which he hopes will lead to altruism.