We may take, as examples of this, the problems of the simplest kind, where the principles lay nearest at hand--the mechanical ones. "Why," he asks,[43\1] "do small forces move great weights by means of a lever, when they have thus to move the lever added to the weight? Is it," he suggests, "because a greater radius moves faster?" "Why does a small wedge split great weights?[44\1] Is it because the wedge is composed of two opposite levers?" "Why,[45\1] when a man rises from a chair, does he bend his leg and his body to acute angles with his thigh? Is it because a right angle is connected with equality and rest?" "Why[46\1] can a man throw a stone further with a sling than with his hand? Is it that when he throws with his hand he moves the stone from rest, but when he uses the sling he throws it already in motion?" "Why,[47\1] if a circle be thrown on the ground, does it first describe a straight line and then a spiral, as it falls? Is it that the air first presses equally on the two sides and supports it, and afterwards presses on one side more?" "Why[48\1] is it difficult to distinguish a musical note from the octave above? Is it that proportion stands in the place of equality?" It must be allowed that these are very vague and worthless surmises; for even if we were, as some commentators have done, to interpret some of them so as to agree with sound philosophy, we should still be unable to point out, in this author's works, any clear or permanent apprehension of the general principles which such an interpretation implies. [Note 43\1: Mech. Prob. 4.] [Note 44\1: Ib. 18.] [Note 45\1: Ib. 31.] [Note 46\1: Ib. 13.] [Note 47\1: Περὶ Ἄψυχα. 11.] [Note 48\1: Περὶ Ἁρμον. 14.] Thus the Aristotelian physics cannot be considered as otherwise than a complete failure. It collected no general laws from facts; and consequently, when it tried to explain facts, it had no principles which were of any avail.