2800. Each hand is a semi-ellipse, in which the four fingers are the periphery, the thumb the radius. Both hands together form a perfect ellipse with two radii.
2801. Now, in the ellipse are involved all geometrical figures. The hands include in their movements the whole of geometry.
2802. We can only perceive the forms of nature, because they all reside in ourselves, because we can create them. This, and none other, is the meaning or sense of the doctrine of pre-established harmony.
2803. The sense of touch is also the sense of form. The fingers constitute so perfect an organ, that it is scarcely requisite for us to estimate all its value. In it the whole body is repeated simply in forms, in spiritual motions.
2804. Through the hand the whole planet becomes an object unto us. It is the hand which instructs us how to know this terrestrial world.
2805. The greatest perfection is attained by the greatest variety or multiplied diversity of the organs. The limbs are simply destined for motion, yet feeling also resides in them, because they are invested with integument. Could the limbs therefore divide into motor and tactile members, the conceivable sum total of perfection must be attained. This division is present alone in Man. The feet have become simply locomotive members, because they are those of the sex; but the hands have become tactile members, because they are those of the encephalic animal.
2806. It is not, as has been imagined, the hands, as hands, which confer nobility upon our species, for by their means an essential half of the animality, or the power of locomotion, is lost; but it is the preservation of all possible functions in an animal, and in such a manner that each stands upon its highest grade of perfection. The highest perfection cannot, however, be attained where two functions are attached to one organ. Should both hands and feet exercise the sense of touch, the motion is impaired; should both move the body, then the sense suffers.
2807. The four hands of the Apes are therefore an imperfection, which we have no need to envy them. They can, properly speaking, only climb and grasp with them, but not run. Each gait of theirs becomes therefore ungainly, the horizontal as well as the upright or perpendicular, and they make use of both alternately; because too the act of handling, i. e. of climbing, is their only proper movement. Now, in the act of climbing all the limbs are brought into requisition, and consequently a free voluntary touch and a free progression disappear.
2808. The feet support the body and stand in its service.
2809. The hands are, on the contrary, supported by the body, are free.