(FORTUNE Magazine) – Our last communication with Sidney Hook, who died on July 12, was in a telephone conversation on May 19. Hook was one of the titans of American philosophy; he was also a dazzling and inspiring teacher who had a transforming effect on many of his students, including the present writer. We have often reflected on the value of the five courses we took under him at New York University in the Forties, and ultimately put it at $1.71 billion (in today's dollars). The calculation is based on simple multiplication. It reflects the fact that (a) the five courses involved a total of 180 lecture- hours, (b) Gerald Ford gets $20,000 for a one-hour talk, and (c) Sidney was 475 times more interesting than Gerald. We initiated the May 19 conversation in an effort to track down and clarify a thought that we dimly remembered from student days. The thought was as follows. In discussions about the relative effects on people of heredity and environment, it is often assumed that a belief in environmental causation is more ''progressive,'' or at least more optimistic. This is because the belief lets you think you can create better people just by changing the environment. In fact, we remembered Hook arguing, there is nothing inherently progressive about a belief in human malleability. It might sometimes lead to social progress, but it could also make brainwashing easier for a Hitler or Stalin. In our phone conversation, Hook took us back gently through his long arguments in the Thirties with the ''class science'' of Stalinists who were totally committed to malleabilism (our word), arguing against all evidence that acquired characteristics could be genetically transmitted -- and reviling as agents of the bourgeoisie scientists who persisted in saying this was nonsense. Possibly you are asking who cares -- i.e., who cares whether environmentalist or hereditarian views prevail? Our own sense of the matter is that the recent research findings are far too fascinating to ignore. One finding that left us reeling when we stumbled across it last year was a revelation generated by the department of psychology at the University of Minnesota. Finding: Political attitudes are biologically inherited. Don't laugh. The Minnesota studies are based on serious studies of twins. The findings on political attitudes were reported by professor David T. Lykken, who sprang it on the Society for Psychophysiological Research when he delivered his presidential address several years ago. All the twins were tested on a measure of conservatism called Tellegen's Traditionalism Scale. The data show that identical twins (who are of course genetically indistinguishable) are far more likely to have similar Tellegen scores than are the fraternal twins (who share only about half their genes). In fact, identical twins raised apart -- growing up with different adoptive parents -- are more alike politically than are fraternal twins raised together. To be sure, the Tellegen scale is a rough-and-ready measure. Lykken tells us that it basically measures ''an affinity for traditional values, including strong allegiance to established authority.'' It is probably not much of a predictor about attitudes toward the minimum wage or the quantity theory of money. But Lykken thinks it should predict fairly well in many other areas where traditional values are more involved: in, say, attitudes toward welfare, abortion, gun control, the need for a strong military. Alas, we shall never have a chance to get Sidney Hook's input on the meaning of these data.