490 



SCIENCE. 



[N. S. Vol. XX. No. 511. 



he can among animals, children, defectives, 

 the insane, criminals, paupers, saints, sin- 

 ners, the sick, the well; must know grief 

 and joy— these, as well as the clinic and 

 the laboratory, for here he fronts the bot- 

 tom facts of the world. Next, he must 

 supplement his at best meager first-hand 

 experience with the proxy experience of 

 others as recorded in books. Psychology 

 lives not merely in the study, but where 

 doubt and belief, sanity and inherited in- 

 sanity, struggle together ; where temptation 

 and conscience wage their wars, in the mob, 

 the cloister ; where rage, terror and pity be- 

 come convulsive and sweep all before them, 

 and where love of the lie usurps that of 

 the truth. Once it was thought that the 

 study of pure should precede that of ap- 

 plied science, but we are now coming to 

 almost reverse this maxim in education. 

 So psychology, especially in our practical 

 age and land, must first study and teach 

 how to live, love, learn, labor; must have 

 something to say to all who reflect on re- 

 production, disease, health, and thus must 

 first serve man well if it would later rule 

 him wisely. If this view be correct we 

 must abandon many supposed certainties 

 and finalities, and with faith in a future 

 far greater than the past has been, devote 

 ourselves to severe and unremitting toil 

 perhaps for generations; must often prac- 

 tise that hardest of all forms of self re- 

 straint in our field— the suspense of judg- 

 ment—assured that in the end psychology 

 is to become queen of those sciences that 

 deal with man, and reign among all the 

 humanities somewhat as chemistry and 

 physics are coming to do over the material 

 world, with a method, perhaps, sometimes 

 no less exact and certain than these already 

 have. So we shall at last attain a true met- 

 aphysics of realities behind sense and feel- 

 ing which is the necessary crown of all 

 science when it becomes complete. 



G. Stanley Hall. 



PRESENT PROBLEMS OF ORGANIC 

 CHEMISTRY.* 



There is a strong tendency on the part 

 of some chemists, at the present time, to 

 claim that chemical science in the true 

 sense includes only such portions of our 

 knowledge as can be stated in accurate 

 mathematical terms. One distinguished rep- 

 resentative of this school of chemistry has 

 said, 'It is not in the province of science to 

 explain phenomena,' and another has writ- 

 ten, 'It is not a part of its ultimate object 

 {i. e., of natural science) to acquire knowl- 

 edge in regard to mentally conceived ex- 

 istences, such as the atoms of matter, or 

 the particles of luminiferous ether, which 

 are of such a magnitude and character as 

 to lie far beyond the limits of human per- 

 ception.' I think that nearly all of those 

 now actively engaged in working over the 

 problems of organic chemistry would dis- 

 sent strongly from these statements. Long 

 experience in dealing with the cumulative, 

 non-mathematical evidence upon which our 

 knowledge of chemical structure is founded 

 has led to a very firm conviction that hu- 

 man knowledge is not bounded by the limits 

 of sense-perception. "We are inclined 

 rather to the view that, while there are, 

 undoubtedly, many things which will 

 always remain beyond any direct cognizance 

 of our senses, yet, so far as these have a 

 real existence we may in the end secure, 

 regarding them, very practical and positive 

 knowledge. It is impossible to conceive 

 that those theories with regard to structure 

 which have guided the work of thousands 

 of chemists for the last fifty years do not 

 in some measure express the actual truth 

 with regard to atoms and their relation to 

 each other in organic compounds. 



Let us follow, for a few moments, in very 

 brief outline, the steps which have led to 

 the present standpoint. So far as the mat- 



■" Read at the International Congress of Arts 

 and Science in St. Louis, September 21, 1904. 



