an enduring position for non-biological, non-physiological psychology.
My investigation may be objected to as in certain points not being supported by enough proof, but I see little force in such an objection. For in these matters what can "proof" mean? I am not dealing with mathematics or with the theory of cognition (except with the latter in two cases); I am dealing with empirical knowledge, and in that one can do no more than point to what exists; in this region proof means no more than the agreement of new experience with old experience, and it is much the same whether the new phenomena have been produced experimentally by men, or have come straight from the creative hand of nature. Of such latter proofs my book contains many.
Finally, I should like to say that my book, if I may be allowed to judge it, is for the most part not of a quality to be understood and absorbed at the first glance. I point out this myself, to guide and protect the reader.
The less I found myself able in both parts of the book (and especially in the second) to confirm what now passes for knowledge, the more anxious I have been to point out coincidences where I found myself in agreement with what has already been known and said.
I have to thank Professor Dr. Laurenz Müllner for the great assistance he has given me, and Professor Dr. Friedrich Jodl for the kindly interest he has taken in my work from the beginning. I am specially indebted to the kind friends who have helped me with correction of the proofs.
