Physics (Aristotle/Wikisource translation)/Book VI
Three critical adjectives have been defined: continuous, touching and successive. Continuous objects are fused and have no boundary between them. Touching objects have collocal endpoints, i.e., boundaries. Successive objects are separated by nothing of their own kind. Given these definitions, a continuum cannot be composed of indivisibles. A line cannot be composed of points, for a line is continuous and a point is indivisible. The ends of two points can neither touch nor fuse; how could a point have endpoints? An indivisible has no boundary or endpoints, since that would divide it into "endpoint" and "not-endpoint", into boundary and bounded.