EACH fresh theory of life which is put forward by thinkers will doubtless find a certain number of adherents, even if, as in the present instance, it is unsupported by anything in the nature of experimental evidence. This sort of evidence is just the kind which it is so difficult to obtain, and new theories lead one but very little nearer to the solution of the great problem. Auerbach's brochure contains nothing reallynew, and he clothes his ideas in a considerable amount of verbiage. No one can doubt that life with its characters of growth and development is a form of energy, but the psychical aspects of life have always been a stumbling-block in the full acceptance of a purely physical theory. Ectropism, the term selected by the author, is not entirely a physical theory; he tells us that ectropism is neither materialism nor idealism, neither formalism nor phenomenalism; it is certainly not monism, but, in a certain sense, it is dualistic. From this one learns what ectropism is not, and one could wish that the rest of the book, which tells us what it is, was equally explicit. We must, however, leave those of our readers who are interested in speculations of this nature to unravel it for themselves.
Ektropismus oder die physikalische Theorie des Lebens.
By Felix Auerbach. Pp. v+99. (Leipzig:W. Engelmann, 1910.) Price 2.60 marks.