KNOWLEDGE Hobbes’ Leviathan begins with a chapter ‘Of Sense’ and oVers a resounding manifesto: ‘There is no conception in a man’s mind, which hath not at Wrst, totally, or by parts, been begotten upon the organs of sense The rest are derived from that original’ (L, 9) Other operations of the mind, such as memory, imagination, and reasoning, are wholly dependent on sensation Imagination and memory are the same thing, namely decaying sense: For as at a great distance of place, that which we look at, appears dim, and without distinction of the smaller parts; and as voices grow weak, and inarticulate: so also after great distance of time, our imagination of the past is weak; and we lose (for example) of cities we have seen, many particular streets; and of actions, many particular circumstances (L, 66) Reasoning, Hobbes says, is nothing but reckoning the consequences of general names agreed upon for the marking and signifying of our thoughts; and thoughts are always, for him, mental images (of names or things) derived from sensation ‘They are every one a representation or appearance of some quality, or other accident of a body without us’ (L, 66) There are, according to Hobbes, two kinds of knowledge: knowledge of fact, and knowledge of consequence Knowledge of consequence is the knowledge of what follows from what: the knowledge that keeps order in the constant succession or train of our thoughts It is expressed in language by conditional laws, of the form ‘If A then B.’ Knowledge of fact—the kind of knowledge that we require from a witness—is given by sense and memory Mere reasoning, or discourse, can never end in absolute knowledge of fact, past or to come (L, 42) It is true, as empiricists claim, that we can never acquire information about the world around us, directly or indirectly, without at some stage exercising our powers of sense-perception The weakness of British empiricism lies in its naive and unsatisfactory account of what sense-perception actually consists in Thinkers in the Aristotelian tradition, which Hobbes speciWcally rejected, had emphasized that our senses are powers to discriminate: the power to tell one colour from another, to distinguish between diVerent sounds and tastes, and so on They had emphasized that the senses had an active role in experience: any particular episode of sensing (e.g tasting the sweetness of a piece of sugar) was a transaction between an item in the world (a property of the sugar) and a faculty of a perceiver (the 128