C. Kenneth Waters

Since the fundamental challenge that I laid at the doorstep of the pluralists was to defend, with nonderivative models, a strong notion of genic cause, it is fatal that Waters has failed to meet that challenge. Waters agrees with me that there is only a single cause operating in these models, but he argues for a notion of causal ‘parsing’ to sustain the viability of some form of pluralism. Waters and his colleagues have some very interesting and important ideas about the sciences, involving pluralism and parsing or partitioning causes, but they are ideas in search of an example. He thinks he has found an example in the case of hierarchical and genic selection. I think he has not.

“The question for us,” as Ronald Giere writes in Understanding Scientific Reasoning, “is whether analogies play any role in the JUSTIFICATION of [a] new theory.” Giere’s answer is an emphatic “No.” (Giere 1984, pp. 79-80). Although most philosophers of science would probably qualify Giere’s unmitigated rejection of analogical justification, few attribute much significance to analogical arguments in science. And when philosophers do grudgingly acknowledge an analogical argument, they are hesitant to analyze it.Take, for example, Charles Darwin’s argument for natural selection. It is difficult to deny that the analogy between artificial and natural selection played an important justificatory role. After all, artificial selectibn was the topic of the first chapter of Darwin’s Origin of Species and was referred to in countless arguments throughout the text.2.

Philosophers now treat the relationship between classical genetics and molecular biology as a paradigm of nonreduction and this example is playing an increasingly prominent role in debates about the reducibility of theories in other sciences. This paper shows that the anti-reductionist consensus about genetics will not withstand serious scrutiny. In addition to defusing the main anti-reductionist objections, this critical analysis uncovers tell-tale signs of a significant reduction in progress. It also identifies philosophical issues relevant to gaining a better understanding of what is now happening in genetics and of what we might expect to happen in other sciences.

One would think that after one hundred years of earnest work, Darwinians would know what it is that nature selects for. Yet while some Darwinians argue that nature selects only for genes, others insist that the units being selected for are organisms and groups of organisms. Darwinians have also had difficulty identifying the fundamental principles of their theory. Some think the basic principle is the survival of the fittest; others deny that this principle is an important part of their theory. ;Philosophers of biology think that many of these fundamental issues could be resolved if we had a clearer understanding of evolutionary theory. Traditionally philosophers have tried to clarify scientific theories by formulating their central laws as universal statements in a formal language. This approach has been challenged recently by those who argue that theories should be thought of as sets of models, not as sets of universal statements. The central aim of my dissertation is to demonstrate how this shift in focus from statements to models can help resolve several long-standing problems associated with the theory of natural selection. ;In the first chapter, I identify the fundamental principles of Darwin's original theory of natural selection. I do so by ignoring Darwin's generalizations and focusing on the models of natural selection presented in the Origin as imaginary illustrations. I clarify Darwin's analogical argument for natural selection in the second chapter. My analysis is based upon the view that analogical reasoning involves using specific information about one model to infer specific information about isomorphic models. In the third chapter, I argue that the principle of the survival of the fittest is untestable and plays no role in specifying the models of natural selection. The fourth chapter concerns the units of selection controversy. I argue that many selection processes can be accounted for by more than one model and that the choice between them is often a pragmatic one. While the four chapters deal with different problems, they are related by their common perspective on the structure of scientific theories, a perspective which I suggest is largely responsible for their individual successes