of primitive people who lived amidst rocks and ice; the tearing off of wallpaper is an atavism of the tearing off of the bark of trees etc. What is most remarkable of all is that the error leads Blonsky to the same conclusion as Hall: to the negation of play. Groos and Stern have shown that exactly where it is easiest to find analogies between onto- and phylogenesis is this theory untenable. And neither does Blonsky, as if illustrating the irresistible force of the methodological laws of scientific knowledge, search for new terms. He sees no need to attach a “new term” (play) to the child’s activity. This means that on his methodological path he first lost its meaning and then—with creditable consistency—refrained from the term that expresses this meaning. Indeed, if the activity, the child’s behavior, is an atavism, then the term “play” is out of place. This activity has nothing in common with the play of the tiger as Groos demonstrated. And we must translate Blonsky’s declaration “I don’t like this term” in methodological terms as “I lost the understanding and meaning of this concept.”

Only in this way, by following each principle to its ultimate copclusions, by taking each concept in the extreme form toward which it strives, by investigating each line of thinking to the very end, at times completing it for the author, can we determine the methodological nature of the phenomenon under investigation. That is why a concept that is used deliberately, not blindly, in the science for which it was created, where it originated, developed, and was carried to its ultimate expression, is blind, leads nowhere when transposed to another science. Such blind transpositions of the biogenetic principle, the experiment, the mathematical method from the natural sciences, created the appearance of science in psychology which in reality concealed a total impotence in the face of the studied facts.

But to complete the sketch of the circle described by the meaning of a principle introduced into a science in this way, we will follow its further fate. The matter does not end with the detection of the fruitlessness of the principle, its critique, the pointing out of curious and strained interpretations at which schoolboys poke their finger. In other words, the history of the principle does not end with its simple expulsion from the area that does not belong to it, with its simple rejection. After all, we remember that the foreign principle penetrated into our science via a bridge of facts, via really existing analogues. Nobody has denied this. While this principle became strengthened and reigned, the number of facts upon which its false power rested increased. They were partially false and partially correct. In its turn the critique of these facts, the critique of the principle itself, draws still other new facts into the scope of the science. The matter is not confined to the facts: the critique must provide an explanation for the colliding facts. The theories assimilate each other and on this basis the regeneration of a new principle takes place.

Under the pressure of the facts and foreign theories, the newcomer changes its face. The same happened with the biogenetic principle. It was reborn and in psychology it figures in two forms (a sign that the process of regeneration is not yet finished): (1) as a theory of utility, defended by neo-Darwinism and the school of Thorndilce, which finds that individual and species are subject to the same laws— hence a number of coincidences, but also a number of non-coincidences. Not everything that is useful for the species in its early stage is useful for the individual as well; (2) as a theory of synchronization, defended in psychology by Koffka and the school of Dewey, in the philosophy of history by Spengler.3° It is a theory which says that all developmental processes have some general stages, some successive forms, in common—from elementary to more complex and from lower to higher levels.

Far be it from us to consider any of these conclusions the right one. We are in general still far from a fundamental examination of the question. For us it is