METAPHYSICS It is, of course, only at one particular level that Darwin’s system offers to render teleology superfluous Human beings, such as husbandmen, act for the sake of goals not only in breeding improved stock, but in human life and business in general Others among the higher animals not only act on instinct, but pursue goals learnt by experience Moreover, Darwinian scientists have not given up the search for final causes Indeed, contemporary biologists are much more adept at discerning the function of structures and behaviours than their predecessors in the period between Descartes and Darwin What Darwin did was to make teleological explanation respectable by offering a general recipe for translating it into an explanation of a mechanistic form His successors thus feel able freely to use such explanations, without offering more than a promissory note about how they are to be reduced to mechanism in any particular case Once they have identified the benefit, G, that an activity or structure confers on an organism, they feel entitled to say without further ado that ‘the organism evolved in such a way that G’ Two great questions about teleology are left unanswered by the work of Darwin First, are the free and conscious decisions of human beings irreducibly teleological, or can they be given an explanation in mechanistic terms? There are those who believe that when more is known about the human brain it will be possible to show that every human thought and action is the outcome of mechanistic physical processes This belief, however, is an act of faith; it is not the result of any scientific discovery or of any philosophical analysis Second, if we assume that broadly Darwinian explanations can be found for the existence of the teleological organisms we see around us, does our investigation rest there? Or can the universe itself be regarded as a system that operates, through mechanistic means, to the goal of producing species of organisms, in the way that a refrigerator works through mechanistic means to the goal of a uniform temperature? Is the universe itself one huge machine, a goal-directed system? Biologists are divided whether evolution itself has a direction Some believe that it has an inbuilt tendency to produce organisms of ever greater complexity and ever higher consciousness Others claim that there is no scientific evidence that evolution has any kind of privileged axis Either way, the question remains whether it is teleological explanation or mechanistic explanation that is the one that operates at a fundamental level of 177