This article critically assesses the empirical research that leads Quine, in his posthumously published work, to abandon his empiricist principle that humans do not have any innate concepts, or knowledge. It is the same empirical research that Penelope Maddy capitalizes on to develop her own contributions to naturalized epistemology, and it has been pioneered by developmental psychologist Elisabeth Spelke. Spelke employs the method of habituation and preferential looking to argue that human infants have innate concepts, and that they have some (...) knowledge about what can and cannot happen to physical objects. Taking into account empirical studies as well as methodological considerations, this article examines whether this research can support these strong philosophical conclusions drawn from it, finding that it likely cannot provide such support. (shrink)