for the bow had not responded to you; the arrow left the string only through the archer’s snap and strength, not through the bow itself.

As for the third that belongs to the bow, the evidence for assigning it that share is that you find the arrow, at the end of the first third (1) of its course, still rising until the beginning of the third third (2); then it starts to sink. This stage comes from the arrow itself, because its nature—as you already know (3)—is to descend, while its initial ascent was due to the force the archer had given it. Consider the case of a stone (4): you throw it upward and it continues to climb so long as the thrower’s power sustains it; once the force that lifted it is exhausted (5), its movement turns to descent, which is its natural motion (6).

Another group said: The correct reason is rather that when the archer places the arrow on the string at an even level, neither sloping upward nor downward, the serving beneath the nock lies lower than the lower limb tip (7) of the bow. When he draws fully and releases, the greatest pinch of the release occurs beneath the nock, so the arrowhead must necessarily tilt upward a little; that slight upward tilt of the head (8) is what produces the considerable elevation that follows.