THE LIBERTY OF SCIENCE IN THE MODERN STATE. 



305 



anybody who wants to speculate plenty of oppor- 

 tunities offer daily. And these opportunities are 

 honestly made use of. A multitude of books 

 would remain unwritten if only objective things 

 were to be communicated. But the subjective* 

 wants are still so great that I believe I am justi- 

 fied in maintaining that, of our present medical 

 literature, about one-half might safely remain un- 

 published, without doing any damage worth men- 

 tioning to the objective side. 



Now, when we teach, in my opinion, we ought 

 not to look upon this subjective side as an essen- 

 tial object in the doctrine. I believe I now belong 

 to the oldest professors of medicine ; I have taught 

 my science now for over 30 years, and I may say 

 that during these 30 years I have honestly striven 

 to free my mind more and more from all subjective 

 tendency, and to get more and more into the ob- 

 jective current. Nevertheless, I openly confess 

 that I find it impossible to give up subjectivity 

 altogether. Every year I see again and again 

 that, even in points where I had believed myself 

 to be entirely objective, I still retained a large 

 number of subjective ideas. I do not go so far 

 as to require everybody to express himself entire- 

 ly without any admixture of subjectiveness, but I 

 do say that we must set ourselves the task to 

 transmit to the students the real knowledge of 

 facts in the first place, and, if we go further, 

 we must tell them each time : " But this is not 

 proved ; but this is my opinion, my idea, my 

 theory, my speculation." 



This, however, we can only do with those who 

 are already educated and developed. We cannot 

 carry the same method into the elementary schools ; 

 we cannot say to each peasant-boy, " This is a 

 fact, this we know, and that we only suppose." 

 On the contrary, that which is known, and that 

 which is only supposed, as a rule, get so thorough- 

 ly mixed up that that which is supposed becomes 

 the main thing, and that which is really known 

 appears only of secondary importance. There- 

 fore we who support science, we who live in sci- 

 ence, are all the more called upon to abstain from 

 carrying into the heads of men, and most of all 

 into the heads of teachers, that which we only 

 suppose. True, we cannot give facts simply in 

 the shape of raw material ; that is impossible. 

 They must be arranged in a certain systematic 

 order. But we must not extend this arrangement 

 beyond what is absolutely necessary. 



And here I have an objection to make to Herr 

 Nageli's address. Herr Nageli has discussed, 

 certainly in the most measured way, and — you 

 will notice this if you read his address — in a thor- 



56 



oughly philosophical manner, the difficult ques- 

 tions which he has chosen as subjects for his dis- 

 course. Nevertheless, he has taken a step which 

 I consider extremely dangerous. He has done in 

 another direction what is in one way done by ge- 

 neratio cequivoca. He asks that the psychological 

 domain shall be extended not only from animals 

 to plants, but that we shall actually carry from the 

 organic world into the inorganic our conceptions 

 of the nature of mental phenomena. This meth- 

 od of thinking, which is represented by great 

 philosophers, is natural in itself. If any one wants 

 by any means to connect mental phenomena with 

 those of the rest of the universe, then he will 

 necessarily come to transfer mental processes, 

 as they occur in man and the animals of highest 

 organization, to the lower and lowest animals ; 

 then a soul is even ascribed to plants ; further on 

 the cell thinks and feels, and finally he finds a 

 passage down to chemical atoms, which hate or 

 love one another, seek one another, or flee from 

 one another. All this is very fine and excellent, 

 and may after all be quite true. It may be. But, 

 then, do we really want, is there any positive sci- 

 entific necessity for extending the domain of men- 

 tal phenomena beyond the circle of those bodies 

 in which and by which we see them really hap- 

 pening? I have no objection to carbon-atoms 

 having a soul, or to their acquiring a soul by their 

 union with the plastidule ; but I do not knoic how 

 I am to find out whether the thing is so. This is 

 simply playing with words. If I declare at- 

 traction and repulsion to be psychic phenom- 

 ena, then I simply throw Psyche out of the 

 window, and Psyche is Psyche no longer. The 

 phenomena of the human mind may eventu- 

 ally be explained in a chemical way, but for 

 the present, I think, it is not our task to mix 

 up these domains. On the contrary, it is our 

 duty to keep them strictly where we understand 

 them. And as I have always laid stress upon 

 this, that we should not in the first line try to 

 find the transition from the inorganic into the 

 organic, but that we should first of all determine 

 the contrast between the inorganic and the or- 

 ganic, and carry on our investigations among 

 those contrasts in the same way, I now maintain 

 that the only way to progress — and I hold the 

 firmest conviction that we shall not advance at 

 all otherwise — is to limit the domain of mental 

 phenomena to where we really perceive mental 

 phenomena, and not to suppose mental phenomena, 

 where perhaps they may be, but where we do not 

 notice any visible, audible, sensible, in one word, 

 perceptible phenomena, which we might call men- 



