The evolution of the tool, of the harp, of music and song and dance, are all beautifully elaborated; but how about the evolution of the human himself, the development of the basic and intrinsic parts that were in him before he made his first tool or gibbered his first chant?
It is that which you do not consider, and which I call biology.

It is biology in its largest aspects.
"I know I express myself incoherently, but I've tried to hammer out the idea.

It came to me as you were talking, so I was not primed and ready to deliver it.

You spoke yourself of the human frailty that prevented one from taking all the factors into consideration.

And you, in turn,--or so it seems to me,--leave out the biological factor, the very stuff out of which has been spun the fabric of all the arts, the warp and the woof of all human actions and achievements." To Ruth's amazement, Martin was not immediately crushed, and that the professor replied in the way he did struck her as forbearance for Martin's youth.