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[ Pobierz całość w formacie PDF ] works specifically, about how the copying mechanisms work that produce members of such kinds then teaches us that yet a third property is attached to these essential natures, namely, historically proper placement. But on a realist understanding of what it is for properties to be essential, all properties comprised in an essential nature must get joined together by virtue of the way the world works. The world must weld together the distinctive package of properties found in member after member of a given natural kind. There need be no single property responsible for all the others, no single property found among members of no other kind in nature (see 2.2) no, the properties essential to a given kind may individually be rather commonplace, individually found among members of various kinds but it must be a function of the way the world works that around some pair (or triad, etc.) of such commonplace properties enough other properties cluster to yield a combination found in no other kind in nature. It cannot just be a function of how we think of the members of a copied kind that throughout its membership a particu- lar shape is joined to a particular proper function. It must be a function of the copying process itself that produces the members of that kind, that in all such members a shape is joined to a function and to a historically proper placement, and quite possibly to a range of further properties as well, in such a way as to yield a cluster of properties found in no other kind in nature. Artifacts and Other Copied Kinds 139 Now the properties essential to any copied kind typically will be properties that individually are commonplace, capable of showing up in members of other copied kinds. The mating dance of the stickleback fish has the proper func- tion of inducing female conspecifics to engage in reproduc- tive behavior in the case of sticklebacks, this means releasing eggs and this proper function is in fact found in a wide range of other mating dances and behaviors. The shape of the stickleback s dance, its choreography, certainly could be found in copied behaviors selected for a different proper function, even if in fact no such other behaviors have yet gotten selected; it could be the shape of a threat display, for example. But such commonplace properties can be essential prop- erties of a copied kind nevertheless, if the way the world works specifically, the way the copying mechanisms work that produce members of that kind is such as to ensure that whenever a pair (or a triad, etc.) of the properties that uni- formly characterize that kind are present, other characteris- tic properties will likewise be present, yielding an overall combination found in no other kind in nature. The nature of the copying process thus must make the combination of a particular proper function and a particular shape be a suffi- cient condition for the presence of a particular historically proper placement. Or else it must be such that that shape in a copied dance and that historically proper placement for the copying ensure that the dance had that proper function. Or else it must be such that that historically proper placement and that particular proper function are jointly a sufficient condition for could have been present only if there had been the presence of just that shape in the dance. How in general can one tell that the combination of two properties, wherever yielded by the world s workings, is a 140 Chapter 7 sufficient condition for yet a third property? The test of flanking uniformities (2.5) begins by turning this question around, namely, as a question about a necessary condition: how does one tell that for that third property to be absent, in some closely similar kind, one or the other of the first two would likewise have to be absent? The test then notes that for that third property to be absent is for there to be a failure of contrast with one or another of that third property s own contraries. Thus the idea, that the absence of that third prop- erty would require the absence of one or another of the first two properties, gets converted into the thought that a deter- minate departure from that third property would go with an answering departure from one or the other (or both) of the first two. Thus in the case of a copied kind one would ask: would a choreography differing from that of the stickleback s dance in some one fixed way have uniformly gone with either a particular difference in the historical audience of that dance, or a particular difference in the function that led to its getting replicated? And the answer is Yes. Among species other than sticklebacks, dances differing in choreography do go with correspondingly different historical placements with females in those species that are wired to respond with repro- ductive behavior of their own if the proper function of the dance is still that it is a mating dance. Among sticklebacks themselves, dances differing in choreography certainly could have gotten selected for and copied time and time again, if they had had the correspondingly different proper function of being threat displays, or if they had historically gotten shaped by the presence of females correspondingly different in their dispositions to respond by laying eggs. Or consider the familiar household screwdriver. Does it follow from the nature of the copying process that produces Artifacts and Other Copied Kinds 141 members of this copied kind that that distinctive shape and that distinctive proper function together guarantee that the historically proper placement of the copying was an envi- ronment containing standard slotted screws? The test of flanking uniformities turns this question about sufficiency into a question about necessity: was that historical place- ment a necessary condition for that combination of shape and proper function? If items generically akin to simple screwdrivers had instead gotten produced alongside screws bearing a particular different sort of slot say, a cross-shaped [ Pobierz całość w formacie PDF ] |