[Mr. Steinbeck's] virtuosity in a purely technical way has tended to obscure his themes. He has published eight volumes of fiction, which represent a variety of forms and which have thereby produced an illusion of having been written from a variety of points of view…. [Attention] has been diverted from the content of Mr. Steinbeck's work by the fact that when his curtain goes up, he always puts on a different kind of show.

Yet there is in Mr. Steinbeck's fiction a substratum which remains constant and which gives it a certain weight. What is constant in Mr. Steinbeck is his preoccupation with biology. He is a biologist in the literal sense that he interests himself in biological research. The biological laboratory in the short story called The Snake is obviously something which he knows at first hand and for which he has a strong special feeling; and...