Professor Keith Parsons On Darwin the Philosopher

Dr. Parsons recently argued that Darwin engaged in philosophical questions. Given the title to his post, the point is that Darwin was also a philosopher. What does Parsons say is the criteria for when someone is engaging in philosophy, as opposed to science? He says this:
In cases ... where the evidence will not settle the dispute, scientists must employ philosophical arguments. And they do. Therefore, the suggestion that science can simply replace philosophy is wrong for the reason that, as [Thomas] Kuhn observed, scientific debates often embed—or are embedded within—philosophical debates. These philosophical differences often cannot be settled by straightforward empirical means, but must be addressed with philosophical argument. Science cannot replace philosophy because philosophy is an essential part of the scientific enterprise. Kuhn was wrong about many things, but on this point he was absolutely right.
I had commented previously on what makes for philosophy right here. And I have no bone to pick with philosophy per se. But this is an interesting question. I think we can agree that mere reasoning is not equivalent to philosophy, so scientific reasoning is not necessarily doing philosophy. We should also agree that we don't need to wait until everyone agrees that a particular dispute has been settled by science, before we can say scientists are no longer doing philosophy when reasoning about the evidence. This was the case in Darwin's day, but the dispute over evolution has been settled in our day. I think the implications about evolution are settled too. What Parsons needs to do is show why anyone should wait until evolution deniers agree that this dispute has been settled, before saying evolutionists are not doing philosophy. So I see no reason to accept that criteria with regard to his specific example.