"Historical ontology" is not, at first sight, a happy phrase. It is too self-important by half. I have always disliked the word "ontology". It was around, in Latin, in the seventeenth century, naming a branch of metaphysics, alongside cosmology and psychology. Christian Wolff (1729) helped confirm it in use. He thought of ontology as the study of being in general, as opposed to philosophical reflection on individual but ultimate entities such as the soul, the world, and God. If, like myself, you are hard pressed to explain what a study of being in general would be, you can hardly welcome talk of ontology. In the twentieth century the word attracted significant philosophers such as Quine and Heidegger, but their pronouncements, in its name, were bizarre Think of Quine's "To be is to be the value of a variable". And yet, and yet: suppose we want to talk in a quite general way about all manner of objects, and what makes it possible for them to come into being. It is convenient to group them together by talking about "What there is", or ontology. And if we are concerned with the coming into being of possibilities, what is that if not historical?