Metaphysics as the Science of Essence [Metafísica como ciencia de la esencia]

If metaphysics is centrally concerned with charting the domain of the possible, the only coherent account of the ground of metaphysical possibility and of our capacity for modal knowledge is to be found in a version of essentialism: a version that I call serious essentialism, to distinguish it from certain other views which may superficially appear very similar to it but which, in fact, differ from it fundamentally in certain crucial respects. This version of essentialism eschews any appeal whatever to the notion of possible worlds in its account of the nature and ground of metaphysical possibility, for reasons that which I shall endeavour to explain and justify in this paper