34 It^E DURATION OF LIFE. [I. 



but poor consolation to the conscious individual which perishes. 

 Johannes Miiller is therefore right, when in the sentence 

 quoted at the beginning of my lecture, he speaks of an ' appear- 

 ance of immortality' which passes from each individual into 

 that which succeeds it. That which remains over, that which 

 persists, is not the individual itself, — not the complex aggregate 

 of cells which is conscious of itself, — but an individuality which 

 is outside its consciousness, and of a low order, — an indivi- 

 duality which is made up of a single cell, which arises from the 

 conscious individual. I might here conclude, but I wish first, 

 in a few words, to protect myself against a possible misunder- 

 standing. 



I have repeatedly spoken of immortality, first of the uni- 

 cellular organism, and secondly of the reproductive cell. By 

 this word I have merely intended to imply a duration of time 

 which appears to be endless to our human faculties. I have no 

 wish to enter into the question of the cosmic or telluric origin 

 of life on the earth. An answer to this question will at once 

 decide whether the power of reproduction possessed by these 

 cells is in reality eternal or only immensely prolonged, for that 

 which is without beginning is, and must be, without end. 



The supposition of a cosmic origin of life can only assist us 

 if by its means we can altogether dispense with any theory of 

 spontaneous generation. The mere shifting of the origin of 

 life to some other far-off world cannot in any way help us. 

 A truly cosmic origin in its widest significance will rigidly limit 

 us to the statement — omne vivmn e vivo — to the idea that life 

 can only arise from life, and has always so arisen, — to the 

 conclusion that organic beings are eternal like matter itself 



Experience cannot help us to decide this question ; we do 

 not know whether spontaneous generation was the commence- 

 ment of life on the earth, nor have we any direct evidence for 

 the idea that the process of development of the living world 

 carries the end within itself, or for the converse idea that the 

 end can only be brought about by means of some external force. 



I admit that spontaneous generation, in spite of all vain 

 efforts to demonstrate it, remains for me a logical necessity. 

 We cannot regard organic and inorganic matter as independent 

 of each other and both eternal, for organic matter is continually 

 passing, without residuum, into the inorganic. If the eternal 



