But this is no more problematic than saying that even in an environment containing only screws, a hammer is for driving nails. Just as driving nails is what the hammer was designed to do, camouflage is what the black color was designed to do. But thinking that this implies that the moths ought to be colored black even in the new environment is like thinking that a hammer's being for driving nails implies that carpenters ought to be using hammers even in a screwy world. Thanks to Darwin, Brandon and many others, the matter of what an adaption is for is not relative to certain interests and values, nor, therefore, is the matter of what it is supposed to do, should do, ought to do, would be defective if it did not do. The comment is true only if we are talking about the heart as a biological adaptation and about its consequent direct proper function, as opposed to any derived proper functions it might have.
Good roots are roots of the sort that promote the flourishing of a plant.
Remarks like these indicate that he has a quite different notion of function in mind, not the one involved when the theory, following Darwin via Brandon, talks of what a biological adaptation is for. Furthermore, there are contexts in which we are rightly interested in functions in this sense, as for example when the issue is whether a certain trait is adaptive in the present environment, or when we are trying to predict its fitness in a new one. At the same time, Harman appears to accept no such pluralism as regards notions of function, at least not here. He rejects the natural-selective account of the proper function of biological adaptations on the ground that function thus conceived does not conform to the notion of function he has in mind, according to which organs function toward what we take to be their flourishing whether or not evolution by natural selection has occurred, and in new environments as well as old. His method is to use a received notion of function to deny that there is a real feature in the world which is both accounted for in natural-selective terms by inference to the best identity or equivalence and legitimately referred to as what an adaptation is for, its function.