Theoretical or speculative science is not philosophy

Continuing the topic of unification, it seems that Kim Sterelny's book The Evolved Apprentice (2012) could be an actual example of naturalistic philosophy that has as its goal the unification of the sciences. In my previous post I was sceptical of philosophers' ability to contribute to such a project, and made the point that in any case it should be called theoretical science, not philosophy.

Here is Tim Lewens' review:

"As philosophers have begun to express scepticism with traditional briefs for their discipline - including various forms of conceptual analysis and metaphysical speculation - some have suggested instead that our role should be to draw together the results of many different sciences, with the aim of providing a balanced and coherent image of our place in nature that is both conceptually disciplined and properly grounded in empirical enquiry. One problem levelled at this synthetic mission-statement for philosophy is that it makes the business too demanding: it is simply implausible that anyone can attain the necessary critical mastery of such a wide range of fields. Kim Sterelny's wonderful new book, which knits together results from ethnography, theoretical biology, cognitive science, and biological anthropology, constitutes an intimidating possibility-proof for others who would aim at such syntheses." (Review of Kim Sterelny: The Evolved Apprentice, 2013)

Note how useless mainstream philosophy is for this kind of work:

"there is comparatively little philosophy in this book, if by 'philosophy' one means the sort of discussion that goes on in the pages of our professional journals. There isn't even much philosophy of science." (ibid.)

So far, so good. But then Lewens tries to argue that this should still be called philosophy:

"The account is nonetheless philosophical, partly because of its speculative nature, partly because Sterelny's synthesis is an armchair activity parasitic on the empirical work of others, and partly because the sort of conceptual ground-clearing loved by philosophers is essential as the elements of Sterelny's story are combined." (ibid.)

Why would being speculative make it a philosophical account instead of just a general scientific hypothesis waiting to be confirmed by further empirical inquiry? And why would being an armchair activity make it philosophical instead of just ordinary theoretical science? After all, there is a lot of useful scientific activity that is quite far away from direct empirical work, i.e. theoretical and computational neuroscience as opposed to wet-lab experiments, and nobody would call it philosophy. "Conceptual ground-clearing" is also an essential part of ordinary scientific research and cannot be separated from the empirical part. Philosophy does not "own" conceptual clarification.