The obsolescence of philosophy is often taken to be a consequence of science. After all, science has a history of repeatedly inheriting—and definitively answering—questions over which philosophers have futilely hemmed and hawed for unconscionable amounts of time. It's been that way from the beginning. Those irrepressible ancient Greeks, Thales & Co., in speculating about the ultimate constituents of the physical world and the laws that govern its changes, were asking questions that awaited answers from physics and cosmology. And so it has gone, science transforming philosophy's vagaries into empirically testable theories, right down to our own scientifically explosive period, when the advancement of cognitive and affective neuroscience has brought such questions as the nature of consciousness, of free will, and of morality—those perennials of the philosophy curriculum—under the gaze of fMRI-enhanced scientists. Philosophy's role in the business of knowledge—or so goes the story—is to send up a signal reading "Science desperately needed here." Or, changing the metaphor, philosophy is a cold storage room in which questions are shelved until the sciences get around to handling them. Or, to change the metaphor yet again, philosophers are premature ejaculators who descant too soon, spilling their seminal genius to no effect. Choose your metaphor, the moral of the story is that the history of scientific expansion is the history of philosophical contraction, and the natural progression ends in the elimination of philosophy.
What's wrong with this story? Well, for starters it's internally incoherent. You can't argue for science making philosophy obsolete without indulging in philosophical arguments. You're going to need to argue, for example, for a clear criterion for distinguishing between scientific and non-scientific theories of the world. When pressed for an answer to the so-called demarcation problem, scientists almost automatically reach for the notion of "falsifiability" first proposed by Karl Popper. His profession? Philosophy. But whatever criterion you offer, its defense is going to implicate you in philosophy. Likewise with the unavoidable question—especially for those who argue philosophy's obsolescence—of what it is that we're doing in doing science. Are we offering descriptions of reality and so extending our ontology in discovering the entities and forces utilized in our best scientific theories? Have we learned, as scientific realism would have it, that there are genes and neurons, fermions and bosons, perhaps a multiverse? Or are these theoretical terms not meant to be interpreted as references to things in the world at all but as mere metaphorical gears in the instruments of prediction known as theories? Presumably scientists care about the philosophical question of whether they are actually talking about anything other than observations when they do their science. Even more to the point, the view that science eliminates philosophy requires a philosophical defense of scientific realism. (And if you think not, then that's going to require a philosophical argument.)
A triumphalist scientism needs philosophy to support itself. And the lesson here should be generalized. Philosophy is joined to science in reason's project. Its mandate is to render our views and our attitudes maximally coherent. This involves it in the task of (in Wilfrid Sellars's terms) reconciling the "scientific" and the "manifest" images we have of our being in the world, which also involves philosophy in providing the reasoning that science requires in order to claim its image as descriptive.
Perhaps the old demarcation problem of distinguishing the scientific is misguided. The more important demarcation is distinguishing all that is implicated in and reconcilable with the scientific claims of knowledge. This leads me to hazard a more utopian answer to this year's Edge Question than the one I proposed in the title. What idea should science retire? The idea of "science" itself. Let's retire it in favor of the more inclusive "knowledge."