A PREVIEW OF COMING ATTRACTIONS
So far my examples of speculations have all been ones introduced by scientists making specific claims about items in the world and laws governing them. They are recognizably “scientific,” whether they are “truth-relevant” or “truth-irrelevant.” Now I want to extend the discussion to much more general and abstract speculations introduced by philosophers, scientists, or both, about the world and about methods for gaining scientific knowledge about the world.
I will call them “philosophical.” Suppose that in the course of a “philosophical” investigation (however broadly that is to be understood), the investigator P introduces an assumption h under “theorizing” conditions (i.e., in the course of explaining, etc., and with the idea that it is true, or close to the truth, or a worthy truth contender). Then, using the account of (Scientific Spec) given in section 10 as a template, we can say that h is a truth-relevant “philosophical” speculation for P if and only if P does not know that there is explanatory evidence that h.The speculations I will consider are ones made within or about science. They are important, if only because they have been assumed and promoted by philosophers and scientists who believe that doing so is central to the pursuit and understanding of science. Usually those who introduce these speculations give reasons in favor of them, as Maxwell did for his speculative kinetic-molecular theory. Perhaps some of those who present these reasons believe they are strong enough to satisfy the requirements of A- or explanatory B-evidence. But even if these reasons do not satisfy such requirements (I will argue that they do not), and even if the champions of these speculations admit that they are speculations, the reasons they do offer in support of them can be evaluated in philosophical cases, as well as in scientific ones.
The speculations I will examine are concerned with three topics: simplicity, holism, and a “Theory of Everything.” With respect to the first, there are speculations claiming that the world is simple, that simplicity is a guide to truth, that scientists must aim to provide simple theories, and that even if the world is not simple, scientists must presuppose that it is to do science.
With respect to the second, there are speculations that scientific theories can only be supported “holistically,” not by establishing individual parts, and that in the absence of such holistic support, theories cannot be evaluated. With respect to the third, there are speculations claiming that there exists a “Theory of Everything,” and that even if it has not yet been found, it needs to be found in order for scientists to be able to make the world completely intelligible. In the next four chapters, I will discuss these and related speculations. They are grand and exciting speculations, or at least are considered so by their proponents. Some of these speculations are argued for by those who make them, by offering either epistemic reasons for believing they are true or non-epistemic ones for believing that they need to be assumed to do science. Some are assumed without argument. My aim is to convince you to reject them. I do so, not because they are speculations but because, even considered as speculations, the arguments that have been presented in their favor by their proponents, as well as other possible arguments I will try to construct, do not deserve high marks. These speculations, although believed by many, have little, if any, support and do not need to be made in order to engage in, or understand, science.