"In 1635 Cavalieri published a theory of "indivisibles," in which he considered a line as made up of an infinite number of points, a superficies as composed of a succession of lines, and a solid as a succession of superficies, thus laying the foundation for the "aggregations" of Barrow. Roberval seems... first, or... an independent, inventor of the method; but he lost credit... because he did not publish it, preferring to keep the method... for his own use... a usual thing... of that time, due perhaps to... professional jealousy. The method was severely criticized... especially by Guldin, but Pascal... showed that the method of indivisibles was as rigorous as... exhaustions... they were practically identical. ...[T]he progress... is much indebted to this defence by Pascal. Since this method is... analogous to... integration, Cavalieri and Roberval have... claim... as... inventors of... one branch of the calculus; if it were not for the fact that they only applied it to special cases, and seem... unable to generalize... owing to cumbrous algebraical notation, or to have failed to perceive the inner meaning... concealed under a geometrical form. Pascal... applied the method with great success, but also to special cases only; such as his work on the ."