distinguished from all other species?

Our human-ness is seen most clearly in three main lines: it is
mechanical, psychical and social. Our power to make and use things is
essentially human; we alone have extra-physical tools. We have added to
our teeth the knife, sword, scissors, mowing machine; to our claws the
spade, harrow, plough, drill, dredge. We are a protean creature, using
the larger brain power through a wide variety of changing weapons. This
is one of our main and vital distinctions. Ancient animal races are
traced and known by mere bones and shells, ancient human races by their
buildings, tools and utensils.

That degree of development which gives us the human mind is a clear
distinction of race. The savage who can count a hundred is more human
than the savage who can count ten.

More prominent than either of these is the social nature of humanity.
We are by no means the only group-animal; that ancient type of industry
the ant, and even the well-worn bee, are social creatures. But insects
of their kind are found living alone. Human beings never. Our
human-ness begins with some low form of social relation and increases as
that relation develops.

Human life of any sort is dependent upon what Kropotkin calls "mutual
aid," and human progress keeps step absolutely with that interchange of
specialized services which makes society organic. The nomad, living on
cattle as ants live on theirs, is less human than the farmer, raising
food by intelligently applied labor; and the extension of trade and
commerce, from mere village market-places to the world-exchanges of
to-day, is extension of human-ness as well.