Note 12 — I HISTORICAL

The realization of the limitation of the surface of the globe—following upon the circumnavigation of the world—had no doubt an influence. The fact that the earth is spherical—or at least that it is not flat—(as a matter of fact it is somewhat tetrahedral) was of course known to Aristotle (De Caelo, ii. 14). It has been remarked that this conception was always present to the minds of the authors of all those speculations which have come down from antiquity (Bosanquet, Philosophical Theory of the State, p. 330). But it was not forced upon men’s notice until it was practically demonstrated.