216 SCIENTIFIC THOUGHT. 



and other interests are at work than we have as yet 

 been able to grasp. So long as astronomy was content 

 to observe the orbits and motions of the heavenly bodies 

 from a distance, it indeed appeared possible to define 

 that science as merely " une question d'analyse " ; but in 

 astronomy even, spectroscopy has brought distant objects 

 near to us and opened out endless vistas into a purely 

 descriptive branch of the science, a natural history of 

 the heavens. Still more so is this the case when we fix 

 our gaze on the world immediately surrounding us on 

 the things and events in which we ourselves take an 

 active part. Here two phenomena attract our attention 

 16. the problem of life, and the problem of consciousness 

 mind. or mind. The knowledge which we possess, or imagine 

 we possess, of the latter, which is gained from a purely 

 introspective point of view, the psychological aspect, I 

 leave at present quite out of the question. As external 

 observation through our senses would never have given 

 it ; as in the map of reality which we call nature, we 

 have not even succeeded in accurately locating conscious- 

 ness, I relegate this large department of Thought to 

 a different place in this work. At present we have to 

 do only with the study of nature, the first condition of 



object was to dispel the popular 

 conception that the accuracy and 

 variety of the performances of the 

 human eye could be explained by 

 the precision and complexity of its 

 structure, as if it were an optical 

 instrument of a degree of perfection 

 which could not be equalled by any 

 optician. In the sequel Helmholtz 

 shows how this admiration of a 

 wrongly supposed mechanical per- 

 fection must make room for an 

 admiration of a different kind, as 



" every work of the organic forma- 

 tive power of nature is for us 

 inimitable " ; a remark which really 

 supports the argument in the text 

 ('Vortrage und Reden,' 3. Aufl. 

 1884, vol. i. p. 240, &c.) It is also 

 important to note how Helmholtz 

 traces the imperfections of the eye 

 to its genesis i.e., its development 

 in the embryo. The genetic sup- 

 plements the purely structural ex- 

 amination (ibid., p. 255). 



