614 KEPORT— 1889. 



would carry me beyond the limits I proposed to myself, viz. the mechanism of life in 

 ita simplest aspects. I therefore leave the subject here, adding- one word only. The 

 distinction which has suggested to their authors the words on which I have been 

 commenting is a real one, but it impUes rather the interference with each other of 

 the simultaneous operation of two regulating mechanisms, than an antagonism 

 between two processes of opposite tendencies carried on by the same mechanism ; 

 or, putting it otherwise, that the observed antagonism is between one nervous 

 mechanism and another, and not between two antagonistic functions of the same 

 living material. 



Vitalistn. 



Without attempting to recapitulate, I have a word to say by way of conclusion 

 on a question which may probably have suggested itself to some of my audience. 



I have indicated to you that although scientific thought does not, like specula- 

 tive, oscillate from side to side, but marches forward with a continued and unin- 

 terrupted progress, the stages of that progress may be marked by characteristic 

 tendencies ; and I have endeavoured to show that in physiology the questions 

 which concentrate to themselves the most lively interest are those which lie at the 

 basis of the elementary mechanism of life. 



The word Life is used in physiology in what, if you like, may be called a 

 technical sense, and denotes only that state of change with permanence which I 

 have endeavoured to set forth to you. In this restricted sense of the word, there- 

 fore, the question ' What is Life ? ' is one to which the answer is approachable ; but 

 I need not say that in a higher sense — higher because it appeals to higher faculties 

 in our nature — the word suggests something outside of mechanism, which may 

 perchance be its cause rather than its effect. 



The tendency to recognise such a relation as this is what we mean by vitalism. 

 At the beginning of this discourse I referred to the anti-vitalistic tendency which 

 accompanied the great advance of knowledge that took place at the middle of the 

 century. But even at the height of this movement there was a reaction towards 

 vitalism, of which Virchow,i the founder of modern pathology, was the greatest 

 exponent. Now, a generation later, a tendency in the same direction is manifesting 

 itself in various quarters. What does this tendency mean ? It has to my mind 

 the same significance now that it had then. Thirty years ago the discovery of the 

 cell as the basis of vital function was new, and the mystery which before belonged 

 to the organism was transferred to the unit, which while it served to explain 

 everything was itself unexplained. The discovery of the cell seemed to be a very 

 close approach to the mechanism of life, but now we are striving to get even closer, 

 and with the same result. Our measurements are more exact, our methods finer ; 

 but these very methods bring us to close quarters with phenomena which, although 

 within reach of exact investigation, are as regards their essence involved in a 

 mystery which is the more profound the more it is brought into contrast with the 

 exact knowledge we possess of surrounding conditions. 



If what I have said is true, there is little ground for the apprehension that 

 exists in the minds of some that the habit of scrutinising the mechanism of life 

 tends to make men regard what can be so learned as the only kind of knowledge. 

 The tendency is now certainly rather in the other direction. What we have to 

 guard against is the mixing of two methods, and, so far as we are concerned, the 

 intrusion into our subject of philosophical speculation. Let us willingly and with 

 our hearts do homage to ' divine Philosophy,' but let that homage be rendered out- 

 side the limits of our science. Let those who are so inclined cross the frontier and 

 philosophise ; but to me it appears to be more conducive to progress that we should 

 do our best to furnish professed philosophers with such facts relating to struc- 

 ture and mechanism as may serve them as aids in the investigation of those deeper 

 problems which concern man's relations to the past, the present, and the unknown 

 future. 



• Virchow, 'Alter und neuer Vitalismus,' Archiv filr path. Anat., 1856, vol. ix., 

 p. 1. See also Kiadfleisch, Aerztliche Philosopfiie, Wiirzburg, 1888, pp. 10-13. 



