Origin of Life 229 



" It may be that, by-and-by, philosophers will discover some 

 higher laws of which the facts of life are particular cases — very 

 possibly they will find out some bond between physico-chemi- 

 cal phenomena on the one hand, and vital phenomena on the 

 other. At present, however, we assuredly know of none ; and I 

 think we shall exercise a wise humility in confessing that, for 

 us at least, this successive assumption of different states (exter- 

 nal conditions remaining the same) — this spontaneity of action 

 — if I may use a term which implies more than I would be 

 answerable for— which constitutes so vast and plain a practical 

 distinction between living bodies and those which do not live, 

 is an ultimate fact ; indicating as such, the existence of a broad 

 line of demarcation between the subject matter of biological 

 and of all other science." 



In another passage he wrote : 



"Looking back through the prodigious vista of the past I 

 find no record of the commencement of life, and therefore I am 

 devoid of any means of forming a definite conclusion as to the 

 conditions of its appearance. Belief, in the scientific sense of 

 the word, is a serious matter, and needs strong foundations. 

 To say, therefore, in the admitted absence of evidence, that I 

 have any belief as to the mode in which the existing forms of 

 life have originated, would be using words in a wrong sense. 

 But expectation is permissible where belief is not ; and if it 

 were given me to look beyond the abyss of geologically re- 

 corded time to the still more remote period when the earth was 

 passing through physical and chemical conditions which it can 

 no more see again than a man can recall his infancy, I should 

 expect to be a witness of the evolution of living protoplasm 

 from non-living matter. I should expect to see it appear under 

 forms of great simplicity, endowed, like existing fungi, with 

 the power of determining the formation of new protoplasm 

 from such matters as ammonium carbonates, oxalates, and tar- 

 trates, alkaline and earthy phosphates, and water, without the 

 aid of light. That is the expectation to which analogical rea- 

 soning leads me, but I beg you once more to recollect that I 

 have no right to call my opinion anything but an act of 

 philosophical faith." 



