In a recent article, Wayne (1995) offers a critique of Horwich's (1982) Bayesian explication of the confirmational significance of evidential diversity. Presently, I argue that Wayne's reconstruction of Horwich's account is not faithful to Horwich's original presentation. Because Wayne's reconstruction is uncharitable, his criticisms turn out to be off the mark. I try to provide a more faithful and charitable rendition of Horwich's account. Unfortunately, even this more charitable reconstruction of Horwich's position seems—at best—to provide an incomplete explication of the confirmational significance of evidential diversity.

Andrew Wayne (1995) discusses some recent attempts to account, within a Bayesian framework, for the “common methodological adage” that “diverse evidence better confirms a hypothesis than does the same amount of similar evidence” (112). One of the approaches considered by Wayne is that suggested by Howson and Urbach (1989/1993) and dubbed the “correlation approach” by Wayne. This approach is, indeed, incomplete, in that it neglects the role of the hypothesis under consideration in determining what diversity in a body of evidence is relevant diversity. In this paper, it is shown how this gap can be filled, resulting in a more satisfactory account of the evidential role of diversity of evidence. In addition, it is argued that Wayne's criticism of the correlation approach does not indicate a serious flaw in the approach.

Acupuncture, the traditional Chinese practice of needling to alleviate pain, offers a striking case where scientific accounts in two cultures, East and West, diverge sharply. Yet the Chinese comfortably embrace the apparent ontological incommensurability. Their pragmatic posture resonates with the New Experimentalism in the West—but with some provocative differences. The development of acupuncture in China (and not in the West) further suggests general research strategies in the context of discovery. My analysis also exemplifies how one might fruitfully pursue a comparative philosophy of science that explores how other cultures investigate and validate their conclusions about the natural world.

In two recent papers, I criticized Ronald N. Giere's and Larry Laudan's arguments for ‘naturalizing’ the philosophy of science (Siegel 1989, 1990). Both Giere and Laudan replied to my criticisms (Giere 1989, Laudan 1990b). The key issue arising in both interchanges is these naturalists' embrace of instrumental conceptions of rationality, and their concomitant rejection of non-instrumental conceptions of that key normative notion. In this reply I argue that their accounts of science's rationality as exclusively instrumental fail, and consequently that their cases for ‘normatively naturalizing’ the philosophy of science fail as well.

In a recent essay (1995), Andrew Wayne charges that Bayesian attempts to account for the rule that, ceteris paribus, diverse evidence confirms better than narrow evidence are inadequate. I reply to these criticisms and argue that, on the contrary, one of the Bayesian approaches considered by Wayne does an excellent job of explaining why, and under what circumstances, diverse evidence is valuable.

The standard adaptationist explanation of the presence of a sensory mechanism in an organism—that it detects properties useful to the organism—cannot be given for color vision. This is because colors do not exist. After arguing for this latter claim, I consider, but reject, nonadaptationist explanations. I conclude by proposing an explanation of how color vision could have adaptive value even though it does not detect properties in the environment.

C. L. Hardin has argued that the colour opponency of the vision system leads to chromatic subjectivism: chromatic sensory states reduce to neurophysiological states. Much of the force of Hardin's argument derives from a critique of chromatic objectivism. On this view chromatic sensory states are held to reduce to an external property. While I agree with Hardin's critique of objectivism it is far from clear that the problems which beset objectivism do not apply to the subjectivist position as well. I develop a critique of subjectivism that parallels Hardin's antiobjectivist argument.

Recent versions of objectivism can reply to the argument from metamers. The deeper rift between subjectivists and objectivists lies in the question of how to explain the structure of qualitative similarities among the colors. Subjectivism grounded in this fashion can answer the circularity objection raised by Dedrick. It endorses skepticism about the claim that there is some one property of objects that it is the function of color vision to detect. Color vision may enable us to detect differences in spectral composition without granting us the capacity to detect identities.

In their article “On What It Takes To Be a World”, David Albert and Jeffrey Barrett raise “a rather urgent question about what the proponents of a many-worlds interpretation [of quantum mechanics] can possibly mean by the term ‘worlds’” (1995, 35). I argue that their considerations do not translate into an argument against the Many-Worlds conception of a world unless one requires that the dispositions that measurement devices display through the outcomes they record be explainable in terms of facts particular to the worlds in which those devices do their recording. Granting that their conception of a world takes away the possibility of such an explanation, a Many-Worlds proponent can claim that the Universal quantum state, which does not represent a fact about any world in particular, is enough to ground the dispositions of measurement devices.