[catenate]

There is an invention without which no other invention can spread beyond its inventor. An invention which makes possible inventions beyond the ability of one person to create. An invention which permits a person to do something with their life other than kill for food, skin for clothes, and hide in natural shelters. An invention so important and fundamental, our physical brains and the thoughts of our consciousness are continually shaped by it. An invention so powerful, it defines the scope of what we can accomplish as a species. An invention impossible to leave behind or survive on most of the planet without, as defenseless physically as we are. An invention so complex and manifold, we continually reinvent it, and almost cannot teach more than the barest rudiments to any other species. Have you got it yet?

[krapp]

language?

[catenate]

Communication in any form, but I was thinking of language in particular, yes. :)