consciousness everything is at once physical and psychical. The obscurity of this intellectual situation has arisen according to my conviction solely from the transference of a physical prepossession into the domain of psychology. The physicist says: I find everywhere bodies and the motions of bodies only, no sensations; sensation therefore must be something _entirely different_ from the physical objects I deal with. The psychologist accepts the second portion of this declaration: To him, it is true, sensation is _given_, but there corresponds to it a mysterious physical something which conformably to physical prepossession must be _different_ from sensation. But what is it that is the really mysterious thing? Is it the Physis or the Psyche? or is it perhaps _both_? It would almost appear so, as it is now the one and now the other that is intangible. Or does the whole reasoning involved rest on a fallacious circle? I believe that the latter is the case. For me the elements designated by _A_ _B_ _C_ ... are immediately and indubitably given, and for me they can never afterwards be volatilised away by any considerations which are after all based in every case on their existence.[36] To the department of special research having for its subject the sensory, physical, and psychical province which is not made superfluous by this general orientation and Which cannot be forestalled, the relations of _A_ _B_ _C_ ... only remain to be ascertained. This may be expressed symbolically by saying that it is the purpose and end of special research to find equations of the form _f(A, B, C_, ...) = 0. I hope with this to have designated the point in which I am in opposition to Dr. Carus, with whom I agree so much in other respects. I am obliged, notwithstanding the latter fact, to regard this point as essential, inasmuch as my whole mode of thinking and direction of inquiry have been changed by the view it involves, and because, moreover, I do not believe that the difference in question can be dissipated by any verbal explanations however exact. This whole train of reasoning has for me simply the significance of negative orientation for the avoidance of pseudo-problems. I restrict myself, moreover intentionally here, to the question of sense-perceptions, for the reason that at the start exact special research will find here alone a safe basis of operations. ERNST MACH. FOOTNOTES: