5. Essence and Natural Kinds: When Science Meets Preschooler Intuition 1

It is common practice in philosophy to “rely on intuitions” in the course of an argument, or sometimes simply to establish a conclusion. One question that is therefore important to settle is: what is the source of these intuitions? Correspondingly: what is their epistemological status? Philosophical discussion often proceeds as though these intuitions stem from insight into the nature of things—as though they are born of rational reflection and judicious discernment. If these intuitions do not have some such status, then their role in philosophical theorizing rapidly becomes suspect. We would not, for example, wish to place philosophical weight on intuitions that are in effect the unreflective articulation of inchoate cognitive biases. Developmental psychology has discovered a range of belief sets that emerge in the first few years of life, and which plausibly go beyond the evidence to which the child has had access in that time period. In such cases, it is reasonable to suppose that the belief sets do not derive solely from the child’s rational reflection on her evidence, but rather show something about the way human beings are fundamentally disposed to see the world. (In some cases, the deep-seated dispositions are also shared with non-human animals.) There are many explanations of why we may be fundamentally disposed to see the world in a particular way, only one of which is that metaphysically or scientifically speaking, the world actually is that way. Another explanation may be that it is simply useful and practical to see the world that way—and this may be so even if it misleads us with respect to the metaphysical and scientific structure of reality. One particular way of carving up the world may be, say, efficient from the information processing point of view, without reflecting much about the fundamental nature of reality. Suppose, then, we find that a particular set of philosophical intuitions closely resembles such an early-emerging implicit belief set. This certainly does not establish the falsity of the intuitions, but it should give us reason to subject them to further scrutiny. This is because such a set of intuitions