Originally Posted by
Xei
I understand perfectly what you said. And welcome to this part of the forums by the way, you have been making some nice posts. In fact I believe Popper said that natural selection itself is essentially not science, for the same reason you mentioned. Do you agree?
I'm not so sure. What we're essentially talking about is using implication to attain conclusions from other observations. Well... there's nothing wrong with implication. In fact it's basically as logically sound as anything can be. You don't need empirical evidence for the conclusion if you have empirical evidence for the assumptions and for the inferences. Natural selection is the logical implication of three common observations (variation, inheritance, competition and fitness), along with ubiquitous and simple methods of inference. Once you have the observations of the antecedents, the only work is in deducing the conclusion; you don't actually need to go out and test it. One could argue about the degree of natural selection, but then you could run quantitative simulations on a computer (again using observations of the antecedents, which in this case would include quantitative measures of variation, etc.) and get a quantitative answer... I don't see any reason why this isn't as epistemologically strong as other areas of science.
Indeed it isn't even clear to me where the distinction lies. Isn't this process a necessary part of science? Science builds general models of things that we have never observed directly, but rather inferred from other observations. You could launch a probe into space with a novel trajectory; isn't the prediction of this trajectory exactly what science does? And yet it isn't based on an empirical confirmation of the hypothesis at hand, but rather inferred from other observations, and mathematical inferences. I don't see any difference at all between this and a sufficiently rigorous argument of evolutionary psychology, based entirely on established facts and valid inferences, for the attractiveness of breasts.
As to the more general issue of positivism raised in you and Philosophers' posts: I don't know the ins and outs of it, but tell me if I have the right picture. Positivism is effectively a total misnomer because it is in fact a negative epistemological approach: one starts by allowing that any physical theory could be true, and then by making observations you rule more and more potential hypotheses out, continuously shrinking the space of potential answers. In this way science avoids making any positive claims whatsoever.