limited field, in which, therefore, on condition of remaining in entire ignorance of everything else, they can attain to the most complete knowledge possible; while the philosopher must survey all fields of knowledge, and indeed to a certain extent be at home in them; and thus that complete knowledge which can only be attained by the study of detail is necessarily denied him. Therefore the former may be compared to those Geneva workmen of whom one makes only wheels, another only springs, and a third only chains. The philosopher, on the other hand, is like the watchmaker, who alone produces a whole out of all these which has motion and significance. They may also be compared to the musicians of an orchestra, each of whom is master of his own instrument; and the philosopher, on the other hand, to the conductor, who must know the nature and use of every instrument, yet without being able to play them all, or even one of them, with great perfection. Scotus Erigena includes all sciences under the name _Scientia_, in opposition to philosophy, which he calls _Sapientia_. The same distinction was already made by the Pythagoreans; as may be seen from Stobæus (_Floril._, vol. i. p. 20), where it is very clearly and neatly explained. But a much happier and more piquant comparison of the relation of the two kinds of mental effort to each other has been so often repeated by the ancients that we no longer know to whom it belongs. Diogenes Laertius (ii. 79) attributes it to Aristippus, Stobæus (_Floril._, tit. iv. 110) to Aristo of Chios; the Scholiast of Aristotle ascribes it to him (p. 8 of the Berlin edition), but Plutarch (_De Puer. Educ._, c. 10) attributes it to Bio—“_Qui ajebat, sicut Penelopes proci, __ quum non possent cum Penelope concumbere, rem cum ejus ancillis habuissent; ita qui philosophiam nequeunt apprehendere eos in alliis nullius pretii disciplinis sese conterere._” In our predominantly empirical and historical age it can do no harm to recall this. Chapter XIII.(25) On The Methods Of Mathematics. Euclid’s method of demonstration has brought forth from its own womb its most striking parody and caricature in the famous controversy on the theory of parallels, and the attempts, which are repeated every year, to prove the eleventh axiom. This axiom asserts, and indeed supports its assertion by the indirect evidence of a third intersecting line, that two lines inclining towards each other (for that is just the meaning of “less than two right angles”) if produced far enough must meet—a truth which is supposed to be too complicated to pass as self-evident, and therefore requires a demonstration. Such a demonstration, however, cannot be produced, just because there is nothing that is not immediate. This scruple of conscience reminds me of Schiller’s question of law:—