AT THE PHYSICO-TECHNICAL INSTITUTE 427 



he is still the definite opponent of every kind of metaphysical 

 speculation. Elsewhere, however, Helmholtz guards himself 

 against the accusation that his antagonism to all kinds of 

 metaphysical speculation extended to philosophical inquiry in 

 general : 



' In thus confining the name of Metaphysics to that so-called 

 science which strives by pure thought to formulate conclusions 

 as to the ultimate principles of the coherency of the Universe, 

 I must protest against my objections to metaphysics being 

 transferred to philosophy in general. In my opinion nothing 

 has been so pernicious to philosophy as its repeated confusion 

 with metaphysics. The latter has played much the same part 

 in relation to the former as that which astrology has borne to 

 astronomy. It has been metaphysics that turned the attention 

 of the great majority of scientific amateurs to philosophy, and 

 attracted troops of proselytes and disciples, who no doubt in 

 many cases have wrought more harm than the bitterest 

 opponents could have effected. They were led on by the 

 delusive hope of obtaining insight, with little expenditure of 

 time or trouble, into the deepest order of things and the nature 

 of the human spirit, into the past and future of the world in 

 which lay the main interest that incited so many to take up the 

 study of philosophy, just as the hope of obtaining prognostica- 

 tions for the future formerly led to the fostering of astronomy. 

 What philosophy has so far been able to teach us, or with 

 continued study of the facts involved may one day be able 

 to teach us, is of the utmost interest to the scientific thinker, 

 who must know the exact capabilities of the instrument with 

 which he has to work, that is, the human intellect. But as 

 regards the satisfaction of this dilettante curiosity, or the still 

 more frequent egoism of the individual, these severe and abstract 

 studies will continue to yield only a small and reluctant 

 response : just as the mathematical mechanics of the planetary 

 system, and the calculations of perturbation, are far less popular, 

 despite their admirable systematic completeness, than was the 

 astrological superstition of old days.' 



And it was this position, thus clearly defined some twenty 

 years before, that Helmholtz now took up in the wholly 

 remodelled section of his Physiological Optics, entitled 'On 

 Perceptions in General '. 



