MODERN ASPECTS OF THE LIFE-QUESTION. 75 1. 



made along some one of the various lines of research, and to the mile- 

 stones which mark the epochs of advance along the way which science 

 has traveled. Moreover, we may profitably sum up at such times the 

 work done in particular directions, and encourage ourselves with pro- 

 spective and retrospective glances. In these summings up, however, 

 a difficulty arises. The range of modern scientific thought includes 

 an immense area. The field of knowledge is already so vast that, 

 seen from the vertical distance necessary to make a wide survey, that 

 small portion of it which is familiar to any one individual is scarcely 

 visible. In consequence, to use a mechanical figure, the solid contents 

 of a man's acquirements being given, the depth thereof is inversely as 

 the area covered. He, therefore, who undertakes to speak even for 

 one single department of science distributes his stock of knowledge 

 over so broad a surface that in places it must become dangerously thin. 

 It is, therefore, with a very keen sense of the temerity involved in the 

 undertaking that I ask your attention, during the hour allotted me, to 

 some points which appear to me to have been recently gained in the 

 discussion of the question of life. 



My friend and predecessor, Professor Marsh, opened his excellent 

 address at Saratoga with the question, " What is Life ? " In a some- 

 what different sense I too ask the same question. But I fear it is only 

 to echo his reply, " The answer is not yet." The result, however, can 

 not long be doubtful. " A thousand earnest seekers after truth seem 

 to be slowly approaching a solution." And, though the ignis fatuus 

 of life still dances over the bogs of our misty knowledge, yet its true 

 character can not finally elude our investigation. The progress already 

 made has hemmed it in on every side ; and the province within which 

 exclusively vital acts are now performed narrows with each year of 

 scientific research. 



What now are we to understand by the word " Life " in this dis- 

 cussion ? A noteworthy parallel is disclosed in the progress of human 

 knowledge between the ideas of life and of force. Both conceptions 

 have advanced, though not with equal rapidity, from a stage of com- 

 plete separability from matter to one of complete inseparability. Life 

 is now universally regarded as a phenomenon of matter, and hence, of 

 course, as having no separate existence. But there still exists a cer- 

 tain vagueness in the meaning of the term "life." Two distinct senses 

 of this word are in use ; the one metaphysical, the other physiological. 

 The former, synonymous with mind and soul, at least in the higher 

 animals, has been evolved from human consciousness ; the latter has 

 arisen from a more or less careful investigation of the phenomena of 

 living beings. It need scarcely be said that it is in the sense last men- 

 tioned that the word " life " is used in science. The conception rep- 

 resents simply the sum of the phenomena exhibited by a living being. 



Moreover, the progress which has been made in the solution of the 

 life-question has been gained chiefly by investigation of special func- 



