Thought and Language and Humans and Animals

The aim of the project is to describe the distinctive contribution language makes to human cognition, and to explain the basis for language in the minds of individuals. The research will take the form of a monograph.


A long standing philosophical debate is whether the capacity for language provides humans with the capacity for thought, and whether only linguistic creatures are capable of thinking. Can such debates be settled by philosophers a priori when they seem to rest on empirical research in developmental and comparative psychologist about the mental lives of pre-linguistic infants and animals? Some philosophers argue that the kind of cognition studied by psychologists is irrelevant to the kind of complex thought exhibited by language users. But if thought is be defined in a way that makes it too close to language - the kind of thing voiced by language users - the issue becomes verbal and the power of the case that language is necessary for thought is lost. To avoid begging the question, we need a way to join the debate between philosophers and psychologists by asking if language provides us with a form of thinking other creature's lack. My project is to show that while language is not necessary for thinking - there can be thought without language - it is necessary for thought about thought. The later capacity depends on the structure of thought made possible by the structure of language; namely logical form; while the form of pre-linguistic thinking is primarily spatial.


The capacity for reflective thought made possible by the capacity for language marks an important division between the kinds of minds possessed by humans and animals. Some: creatures have minds and some creatures have minds and know that they have minds. My research will show that language marks this boundary.


There are several important consequences of this view. Language will be shown to be necessary for our mentalising ability to attribute mental states to ourselves and others, and so will play a fundamental part in self-knowledge.
Creatures without language will lack these mentalising abilities (often known as 'theory of mind'); and thus my proposal requires me to argue against the conclusions drawn by some primatologists that chimpanzees and monkeys have a theory of mind. There will be a chapter reviewing the evidence and contesting the claims based on it. I shall also consider counter-evidence from primatology in the work of Daniel Povinelli.


Since language is a necessary condition for recognising people's mental states, language acquisition cannot depend on the prior ability to recognise others' intentions. It is not by knowing what other people think or intend that we first figure out what they mean by their words. An account will be offered of how individuals acquire language. Our knowledge of syntax requires no knowledge of other minds and is largely due to an innate linguistic system. However, knowledge of word meaning does not belong to the innate language faculty and must be acquired in a public and social context. Word meanings are learned before the advent of grammar in the child's speech. One word and two word combinations exist before sentence structure and I will conclude that at this stage word meaning is not essentially linguistic, but instead reflects our general representational capacities for joint perception and classification. Thus what we call language proper is the upshor of two quite different cognitive systems created when the linguistic system for syntactic structure comes on stream around 20-24 months and recruits existing word meanings into particular syntactic roles. Forms of thinking emerge at this stage that were previously unavailable, and which distinguish human cognition from the cognition of all other creatures.


An important part of this project is to explain knowledge of word meaning in terms of both the inner and conscious aspect of comprehension and the outer and public dimension of speech.