As announced, I'm (belatedly!) planning to comment here section-by-section on Penelope Maddy's Second Philosophy: A Naturalistic Method (OUP, 2007). Let me say straight away, having read on a hundred pages or so, that I have nothing but praise for Maddy's writing style, which I can only envy. This is a remarkably readable book. And perhaps I should add that I am also highly sympathetic to the kind of naturalistic project that she is pursuing: so it might turn out that my remarks here won't be that interesting (vigorous and acerbic criticism always being so much more fun to read!). But let's see ...
Who is the 'Second Philosopher'? She espouses a kind of 'naturalism' -- but that descriptive label has been used so variously, "to mark little more than a vague science-friendliness", as to become unhelpful. So over the opening chapters of the book, Maddy aims to characterize the Second Philosopher, not by giving a sharp definition of her position, but by means of a "character sketch", illustrating her philosophical disposition. But this much is clear from the outset: in her pursuit of truth, the Second Philosopher "rejects authority and tradition as evidence, she works to minimize prejudices and subjective factors that might skew her investigations." Rather, "she uses what we typically describe with our rough and ready term 'scientiﬁc methods'" though she avoids trying to give a definitive account of what that entails. She is open minded about how best to increase her knowledge; "she simply begins from commonsense perception and proceeds from there to systematic observation, active experimentation, theory formation and testing, working all the while to assess, correct, and improve her methods as she goes".
That perhaps makes it sound as if the Second Philosopher is just a scientist. But she has, as we will see in due course, a taste for some very general questions about the world and our epistemic relation to it and the concepts we bring to describe it, as well as for more local questions. And it is this (a matter of the range of her interests rather than of her intellectual methods) that distinguishes her from run-of-the-mill scientists. Unlike the working chemist, for example, she addresses "a wide range of questions we would ... typically regard as 'philosophical'" -- but she doesn't sense a crashing of the gears as she turns from narrower scientific questions to the more sweeping 'philosophical' ones. She has no criterion for sharply demarcating science from philosophy, and she aims to bring to bear the same methods of theory building and testing in her pursuit of truth, whether on the local or more global scale.
We recognize the tone of voice here! Here's Reichenbach (later quoted by Maddy):
Modern science ... has refused to recognize the authority of the philosopher who claims to know the truth from intuition, from insight into a world of ideas or into the nature of reason or the principles of being, or from whatever super-empirical source. There is no separate entrance to truth for philosophers.The Second Philosopher, enlisting with Reichenbach, finds no place for a First Philosophy, prior to science, which can supply a priori principles of justification for science.
But in keeping with her anti-dogmatic stance, her open-minded willingness to test out any ideas that have some hope of advancing knowledge, it isn't that the Second Philosopher is refusing the very possibility of First Philosophy on the basis of some priori argument (after all, she isn't that keen on a priori arguments!). Rather, "[h]er reaction to extra-scientiﬁc philosophy is puzzlement; she asks methodically after its standards and goals, and assesses these by her own lights." She looks case-by-case at what is on offer from those who do have ambitions towards a First Philosophy and she finds herself quite unpersuaded by their offerings.
This is, in particular, her view of Descartes's project, as he engages in his Meditations on First Philosophy. He is promising, after all, a new method to put all future science on a firmer footing. So of course the Second Philosopher will sit up and take notice: she's all for anything that will improve science. As Maddy puts it,
When Descartes proposes that she adopt his Method of Doubt, she doesn’t reject it as 'unscientific'; impressed by the promised pay-off -- a firmer foundation for her beliefs -- she’s quite willing to give his proposal a try; she eventually discards it only as it proves ineffective.The story is spelt out in more detail in Maddy's first chapter, so let's turn to that.