Superstition is generally understood as the paradigmatic example of irrationality. While this view is correct in so far as it goes, it fails to explain two very significant questions. Firstly, why it is that superstitious thinking should arise in evolved beings when it would seem that it is an impediment rather than an aid in survival. Secondly, why superstition, itself, should have not just survived but done very well despite ongoing efforts to weed it out. Both questions become much easier to answer when we see superstition not as the opposite of rationality but, rather, as the lamentable by-product of the limited cognitive capabilities and mechanisms available to us. Indeed, once we understand that rationality is bounded, systematic shortcomings such as superstition become predictable. And, while it is impossible to know at this point the actual evolutionary history of superstition, it should be possible to see how it could be that superstition could arise in organisms undergoing evolutionary change. This naturalist theoretical framework allows us to look at a number of interesting issues regarding superstition. The first is the possibility of characterising superstition, as opposed to false or irrational beliefs in general. The second is to try and understand the relationship between superstitious beliefs and superstitious practices. The third is to see to what degree and for what reasons superstition is a problem. The fourth is the nature of the relationship between superstition and another element of human beliefs that would seem surprising from a purely rational point of view – religious beliefs. The fifth is to examine which of our cognitive mechanisms fail us and cause superstition to be so attractive to us. The sixth is whether superstition is a necessary element of human nature or if its influence may be eliminated. The overall aim of the project, therefore, is to fit superstition into a thoroughly naturalised world view, and, in particular, a naturalised view of rationality as bounded and evolved. The hope is that the result will be to cast light upon superstition and, in reflection, upon rationality.