You have come out of the trees so recently, and your kinship with the monkeys and lemurs is still so strong, that you tend toward abstraction without being able to part with the palpable—firsthand experience. Therefore a lecture unsupported by strong sensuality, full of formulas telling more about stone than a stone glimpsed, licked, and fingered will tell you—such a lecture will either bore you and frighten you away, or at the very least leave a certain unsatisfied need familiar even to lofty theoreticians, your highest class of abstractors, as attested by countless examples lifted from scientists’ intimate confessions, since the vast majority of them admit that, in the course of constructing abstract proofs, they feel an immense need for the support of things tangible.

What I have said up to now is intended to explain why I shall be interlarding my lecture with the images and parables so necessary to you. I do not need them myself; in this I discern no sign of my superiority—that lies elsewhere. The countervisuality of my nature derives from the fact that I have never held a stone in my hand or plunged into slimy-green or crystal-clear water, nor did I first learn of the existence of gases with my lungs in the early morning, but only later by calculations, since I have neither hands for grasping, nor a body, nor lungs. Therefore abstraction is primary for me, while the visual is secondary, and I have had to learn the latter with considerably more effort than was required for me to learn abstraction. Yet I needed this, if I was to erect those precarious bridges across which my thought travels to you, and across which, reflected in your intellects, it returns to me, usually to surprise me.