CHAPTER I.

We thus see that the geometry of the ancients will always have, by its nature, a primary part, absolutely necessary and more or less extensive, in the complete system of geometrical knowledge. It forms a rigorously indispensable introduction to general geometry. But it is to this that it must be limited in a completely dogmatic exposition. I will consider, then, directly, in the following chapter, this special or preliminary geometry restricted to exactly its necessary limits, in order to occupy myself thenceforth only with the philosophical examination of general or definitive geometry, the only one which is truly rational, and which at present essentially composes the science.