This book is the first of two volumes (volume 2 is expected next year) which investigate, from an evolutionary perspective, how human language developed. The current volume deals with semantics and pragmatics; the second will deal with phonetics, morphology and syntax.
Hurford is a professor of linguistics at Edinburgh University. His intellectual position as set out in his Preface is firmly pro-Darwinian and anti-Cartesian and his approach largely empirical. As he admits, his subject has a well deserved reputation for impenetrability. This is unfortunate, since the proper study of language is an interdisciplinary one. Hurford criticises the still widely held view that `linguistics' should deal only with fully developed modern human languages divorced from any biological or historical considerations. The study of language, he rightly asserts, involves precisely such considerations and is drawing in professionals from disciplines which, traditionally, have had only the most tenuous connection with formal linguistics. All have contributions to make and there is a need to find some common ground if collaboration is to be possible. One of his objectives in the current book is to bridge some of the sectarian gulfs which have generally tended to impede cooperative scholarship, and tell a story about the evolution of language which can be widely understood. He attempts this by adopting a practical, common-sense approach and writing in `everyday' language with very little from linguistics and a good deal from other sources.. And I should say straight away that he succeeds admirably: his prose is clear, correct, and agreeable to read; his method is practical; his arguments logical. This is a widely accessible and convincing exposition of an important topic.
The question that Hurford addresses is, roughly, `Where did language come from?' After all it must have come from somewhere. No one seriously believes that `language' sprang fully formed from Athena's forehead and Hurford rightly eschews such proposals as `In the beginning was the word', or `The limits of my language mean the limits of my world'. Equally no rational person seriously denies the existence of other minds. But `proving' all this is another matter: thus Hurford needs to account for, firstly, the possibility of pre-linguistic concepts -- hence the discussion in Part 1 of semantics, and, secondly, the hows and whys of communication -- hence the investigation of pragmatics in Part 2.
Much discussion of events on evolutionary time-scales will almost inevitably be speculative. However some speculations are more plausible than others and Hurford uses a wide range of interdisciplinary tools to support his basic premise that language is not necessary for thought. The main thrust of his argument, that `the evolutionary foundations of semantics lie in the internal mental representations that animals have of the things, events and situations in their environment' (p. 5), is supported primarily by animal studies, both in the laboratory and in the wild. He supposes, reasonably enough, that observing animals, particularly those closely related to us, can cast some light on what it might have been to have lived in a world without language. But Hurford also works with developmental psychology, neuroscience, game theory and computer simulations. Most interestingly, perhaps, he combines these approaches with linguistics (`lite' only!) to demonstrate that some higher animals not only have concepts but these can be formalised as simple propositions. Recent research strongly reinforces Hurford's hypothesis.[FOOTNOTE See, for instance, Heinrich and Bugnyar (Scientific American, April 2007) on the use of logic by ravens in problem solving.] He also suggests that (proto-) propositional thinking has specific neural correlates in the dorsal and ventral pathways of the visual system. Hackles may well be raised at this point (if not earlier!). But Hurford's argument is detailed, systematic and persuasive. And, in a way, much of what he says should not really be that surprising -- anyone who has a cat or dog, or a baby will immediately recognise the truth of it.
However, though language may not be a necessary condition of thought, having concepts does seem a precondition of language, and the findings on semantics pave the way for the discussion of interpersonal communication in Part 2. The question is: if animals do have concepts and some very limited capacities for proto-propositional thought, do they communicate about these and if so why and how? Most higher animals live in social groups and it seems fairly obvious that they must, for the group to cohere and survive, communicate about various states of the world e.g. in collaborative hunting or standing sentry or giving alarm calls. Most animal communication is by dyadic interaction, involving a sender and a receiver. This does not involve a `third party' and is non-referring. Under the right conditions, this can develop along a logical path to triadic communication in which the sender draws the receiver's attention to some object or event. There is some evidence for this kind of communication between animals in relation (for example) to food sharing. But the main mechanism of triadic communication is deictic or indexical pointing, which draws attention to an object without asserting anything about it, and there is no real evidence that animals in the wild ever do this, though apes in captivity can be trained to do it to a limited extent. Hurford ponders why humans alone developed this skill, which started us off on the royal road to language, and surveys a wide range of evolutionary theories that could explain it. The detailed discussion is beyond the scope of this review. Suffice it to say that Hurford tells a convincing and fascinating story. A great deal of this is amusing as well as informative -- I was delighted to learn that rats really do dream about running mazes, apes sulk and lie, and, contra Wittgenstein, we might well be able to understand a lion if it considered us worth talking to. And although the story told so far can stand alone, there is the distinct sense that it is far from finished and I look forward to seeing how the plot unfolds in Hurford's next volume.