of Mind: {{Quotation | "To possess a dispositional property is not to be in a particular state, or to undergo a particular change, it is to be bound or liable to be in a particular state, or to undergo a particular change, when a particular change is realized." | Gilbert Ryle| The Concept of Mind, 1949'}} While this dispositionalism quite successfully deals with the objection that one can feel or think one thing and do another, it is not enough - "it seems obvious as anything is obvious that there is something actually going on in me that constitutes my thought". Ryle's Dispositional Behaviourism denies this, and so Armstrong declares it to be "unsatisfactory as a theory of mind". Though he rejects Behaviourism, Armstrong suggests that it is useful to say that the mind and mental states are "logically tied to behaviour". He says that "thought is not speech under suitable circumstances, rather it is something within the person that, in suitable circumstances, brings about speech." He thinks this view is compatible with a Materialist view of the mind, though it is also compatible with non-Materialist views, such as Descartes'. Armstrong modifies Ryle's Behaviourism by suggesting that the mind's dispositions may be explainable by science in Materialist terms, in the same way that glass's brittleness can be explained in terms of molecular structure. Armstrong offers this view as a true account of the mind. It is more fully developed in Belief, Truth and Knowledge (1973), ch. 2, sect. 2. Armstrong brings together two earlier conclusions: that the mind is "that which stands behind and brings about our complex behaviour"; and that the Behaviourist's dispositions are "states that underlie behaviour and, under certain circumstances, bring about behaviour", and reaches "a conception of a mental state as a state of the person apt for producing certain ranges of behaviour". The Problem of Consciousness Armstrong now addresses what he calls 'the problem of consciousness': how can the personal experience of consciousness be explained by his Materialist theory of the mind? Armstrong considers times when the brain goes on 'auto-pilot' - during long drives without breaks, one might suddenly 'come to' and realize that while one has stayed on the road, stopped at red lights and operated the clutch, one was completely unaware of doing so. This shows that it is possible for mental processes to take place without conscious experience. Before considering how