  By a closure space we will mean a pair $(A,\mathcal{C})$, in which $A$ is a
set and $\mathcal{C}$ a set of subsets of $A$ closed under arbitrary
intersections. The purpose of this paper is to initiate a development of
descent theory of closure spaces, with our main results being: (a)
characterization of descent morphisms of closure spaces; (b) in the category of
finite closure spaces every descent morphism is an effective descent morphism;
(c) every surjective closed map and every surjective open map of closure spaces
is an effective descent morphism.
