bones are, that the hammer and spade are also; they differ in the
degree of closeness and permanence with which they are associated
with protoplasm, but both bones and hammers are alike non-living
things which protoplasm uses for its own purposes and keeps closer
or less close at hand as custom and convenience may determine.

According to this view, the non-protoplasmic parts of the body are
tools of the first degree; they are not living, but they are in such
close and constant contact with that which really lives, that an
aroma of life attaches to them. Some of these, however, such as
horns, hooves, and tusks, are so little permeated by protoplasm that
they cannot rank much higher than the tools of the second degree,
which come next to them in order.

These tools of the second degree are either picked up ready-made, or
are manufactured directly by the body, as being torn or bitten into
shape, or as stones picked up to throw at prey or at an enemy.

Tools of the third degree are made by the instrumentality of tools
of the second and first degrees; as, for example, chipped flint,
arrow-heads, &c.

Tools of the fourth degree are made by those of the third, second,
and first. They consist of the simpler compound instruments that
yet require to be worked by hand, as hammers, spades, and even hand
flour-mills.

Tools of the fifth degree are made by the help of those of the
fourth, third, second, and first. They are compounded of many
tools, worked, it may be, by steam or water and requiring no