1906.] o/i The Physical Basis of Life, 393 



intelligible o-round for refusing to say tlitit the properties of proto- 

 plasm result from the nature and disposition of its molecules. 



" But I bid you beware that, in accepting these conclusions, you 

 are placing your feet on the first rung of a hidder wliicli, in most 

 people's estimation, is the reverse of Jacob's, and leads to the anti- 

 podes of heaven. It may seem a small thing to admit that the dull 

 vital actions of a fungus or a foraminifer are the properties of their 

 protoplasm, and are the direct results of the nature of the matter of 

 which they are composed. But if, as I have endeavoured to })rove 

 to you, their protoplasm is essentially identical with, and most readily 

 converted into, that of any animal, I can discover no logical halting- 

 place between the admission that such is the case and the further 

 concession that all vital action may, with equal propriety, l)e said to 

 be the result of the molecular forces of the protoplasm which displays 

 it. And if so, it must be true, in the same sense and to the same 

 extent, that the thoughts to which I am now giving utterance, and 

 your thoughts regarding them, are the expression of molecular 

 changes in that manner of life which is the source of our other vital 

 phenomena." 



This uncompromising, virile attitude towards the most difficult 

 and stupendous problem of science is characteristic both of the man 

 and of the time. Huxley wrote in 18G8 at the zenith of a period of 

 strenuous intellectual life without doubt unsurpassed in the history 

 of the world. The strong new wine of scientific discovery was 

 running in men's veins. 



A mere chronological table of the chief scientific events shows 

 how fast was the growth. In the forties the labours of Joule pro- 

 vided a basis for the conception of the conservation of energy which 

 at a step unified all the sciences. In the forties, too, the unification 

 of the biological sciences Avas begun by the recognition of the cell 

 as the unit of all life, and of the glutinous sarcode as its physical 

 basis, and was crowned by the publication of The Orif/in of Species in 

 18.59, which gave force and authority to the older doctrine of the 

 continuous development and progression of life. 



The spirit of the age was one of conflict, and men's minds were 

 turned by it to Pisgah-like visions of the country to be conquered. 

 The ideal of the new learning was the unity of all knowledge, its 

 quest the establishment of a scheme of things animate and inanimate 

 which should show them, linked together, without break, in orderly 

 progress from the simple to the complex, from the lower to the 

 higher, and its duty the warfare against a piecemeal and partial out- 

 look of separate creation and catastrophic change. For the new 

 learning no one did l)attle more strenuously than did Huxley. 



The doctrine of the unity of knowledge and experience is not an 

 easy one : it is justified even now rather by the steady trend of 

 science than by its completed demonstrations. Knowledge may be 

 seen to be growing from the sides of many a chasm like the two arms 



