On The Gait Of Animals
inferior; in respect to place bipeds have their superior part
corresponding to the part of the universe; quadrupeds, polypods, and
footless animals to the intermediate part, and plants to the inferior.
The reason is that these have no power of locomotion, and the superior
part is determined relatively to the nutriment, and their nutriment is
from the earth. Quadrupeds, polypods, and footless animals again
have their superior part corresponding to the intermediate, because
they are not erect. Bipeds have theirs corresponding to the superior
part of the universe because they are erect, and of bipeds, man par
excellence; for man is the most natural of bipeds. And it is
reasonable for the starting points to be in these parts; for the
starting-point is honourable, and the superior is more honourable than
the inferior, the front than the back, and the right than the left. Or
we may reverse the argument and say quite well that these parts are
more honourable than their opposites just because the
starting-points are in them.
The above discussion has made it clear that the original of movement
is in the parts on the right. Now every continuous whole, one part
of which is moved while the other remains at rest must, in order to be
able to move as a whole while one part stands still, have in the place
where both parts have opposed movements some common part which
connects the moving parts with one another. Further in this common
part the original of the motion (and similarly of the absence of
motion) of each of the parts must lie.
Clearly then if any of the opposite pairs of parts (right and
left, that is, superior and inferior, before and behind) have a
movement of their own, each of them has for common original of its
movements the juncture of the parts in question.
Now before and behind are not distinctions relatively to that
which sets up its own motion, because in nature nothing has a movement