Thorpe’s thesis in his Gifford Lectures is that what distinguishes humanity from the animals is the capacity for religion. He argues this point by developing a strongly non-mechanistic account of animal behaviour in the first part (chapters 1–5), and then comparing human behaviour to discover what is unique in the second part (chapters 6–10).
Chapter 1: Living and Non-living
To what extent is living and non-living an important distinction? To answer the question, there is a need to stray across several sciences, and in particular to use ‘observational’ methodology, more traditional in biological sciences, to explore the physical and chemical world. Modern physics renders older ‘mechanical’ conceptions of the world impossible.
Accounts of life as activity are implausible, as a consideration of a thunderstorm will show. Rather, it is the purposefulness of its constituent parts that render a system ‘alive’. Mitochondria and cell nuclei are for something—planets and nebula and lightning discharges are not. Finally, we must note that living organisms receive, process and respond to information in a way that non-living systems do not.
Chapter 2: Storing, Coding and Accumulation of Information in Simple Organisms and Their Relation to the Processes of Evolution
This chapter addresses the plausibility of believing that the basic processes of life can give rise to the variety and complexity we observe, and of believing that the same processes of evolution can give an account of the start of life. The concept of ‘information’ is foremost: Thorpe first fleshes out his previous assertion that information processing is a distinctive property of life, and then considers the sheer quantity of information necessary for even a basic cell.
Thorpe then turns briefly to a first introduction to mind-body dualism, borrowing from Popper’s ‘three worlds’ (physical, conscious, noetic). The suggestion of a quasi-platonic third ‘world’ of ‘objective knowledge’, if accepted, clearly provides an easy solution to the problem uncovered in the chapter.
Chapter 3: Animal Languages
Given the importance of information in Thorpe’s analysis so far, the possibility of the transfer of information inevitably becomes important. This long chapter first establishes a system for classifying ‘languages’, building on the work of Hockett in distinguishing between sixteen possible features of communication, and then reviews in detail the communicative abilities of a variety of animals, starting with the chemical communication of slime-moulds and working through crustacea and insects to fish, reptiles, birds (drawing on Thorpe’s own work) and, briefly, mammals (humpback whales and bats are the only mammals considered). Thorpe’s point is that the transfer of information between individuals of a species by language-like mechanisms is universal, even in the most primitive animals.
Chapter 4: Innate Behaviour versus Acquired Behaviour
Thorpe next turns to the concept of ‘instinctive behaviour’. Reflex muscular response is not sufficient to account for instinctive behaviour, as such behaviour involves the complex coordination of many muscles, each acting in fairly precise ways. Thorpe illustrates this from creatures as basic (in terms of development of nervous systems) as sea anemones and crabs. Pavlovian ‘associationism’ fares little better: it demonstrates a phenomenon without explaining it. Thorpe turns to his own field of ethology for illumination.
Some animal behaviour is clearly inherited; however, equally clearly, much behaviour is adaptive. Experimental and observational data (which Thorpe again reviews) allow these distinctions to be made, and to be understood in terms of a distinction between ‘innately coded information’ and ‘information which arises elsewhere’, i.e., learned information.
Chapter 5: Animal Perception
If animals learn from their particular environments, they must have some faculty to perceive aspects of that environment. Some learning is mere conditioning (Pavlov, once more), but some involves ‘insight’, ‘the solution of a problem by the sudden adaptive reorganisation of experience’ (p. 174). Experimental data suggests that this ability to reorganise experience is greatly dependent on pattern recognition, a highly developed ability in many animals (again, examples are given at some length). The chapter ends with some speculation on the relation of this pattern recognition to aesthetics: do bird recognise beauty in each other’s plumage or song?
Chapter 6: The Development of Human Behaviour
Thorpe turns from animals to humans. He discusses the (then-) present state of scientific understanding of the development of human behaviour from foetus through infant and child to the formation of social bonds. At each stage he compares detailed analyses of the cause and progress of human development with the development of behaviour in animals that traced in chapter 4 (he focuses here on primates and on birds). His conclusion is that behavioural patterns develop in humans in exactly the same way as they do in mammals, and indeed in birds.
Chapter 7: Aggressive Behaviour
Observations of group behaviour in primates suggest that group-on-group aggression is extraordinarily rare, and always a response to such factors as overcrowding, scarcity of food or invasion of territory. This appears not to be true of human societies, where group violence can stem from nothing more than a cultural predilection to warfare. Studies of the psychology of individual violence in human beings are no more helpful, and Thorpe concludes, hesitantly, that there is something wrong with humanity that leads us to accept or even enjoy violence. At this point, the first explicitly religious moment of the book appears, with a suggestion that this be equated with the New Testament concept of original sin.
Chapter 8: The Uniqueness of Man
Thorpe returns to the question of human uniqueness. He considers two lists of what separates humanity from the animals, one of eight traditional psychological points, and one of four more specific points drawn from Burke. Citing further experimental observations of animal behaviour, he concludes that even such factors as tool use, language, counting and artistic appreciation cannot be used to define a gulf between humanity and the higher animals, at least. Nonetheless, at the end of the chapter he acknowledges that there is a ‘tremendous chasm’ of some sort and suggests that its evolutionary origin will remain necessarily opaque to us.
Chapter 9: Problems of Consciousness
There is much philosophical reflection on the phenomenon of consciousness, but the question now needs to be approached from the perspective of neuroscience. This is important because theorists such as Popper claim that ‘consciousness of selfhood’ is the defining distinction between human and animal. Questions of mind, the relationship of mental faculties to brain structures, free will and even the possibility of paranormal perception (ESP and the like) are discussed in an account of what this consciousness of selfhood involves and implies.
Chapter 10: Emergence and Transcendence
Thorpe finally turns to the notion of emergent properties, i.e., properties arising out of a complex system that could not, in principle, have been predicted in advance. Consciousness in general and self-consciousness in particular are such properties, which in Thorpe’s view spontaneously occur at some moment in the evolutionary process. This leads to some reflection on the dangers and inadequacy of scientific reductionism. Reductionism is logically flawed but also existentially disastrous, as it leads to a loss of meaning. Meaning is, in Thorpe’s view, vital for human existence. This leads him to discuss ‘man as a religious animal’. Self-consciousness, the ability to value abstract concepts such as justice and the search for meaning are the things, finally, that truly differentiate humanity from other animals: our uniqueness is our religiosity. Thorpe closes the book with a rapid exploration of the tenability of various classical religious themes in an evolutionary framework, notably the existence of the soul and the concept of creation.