BIOLOGICAL PHILOSOPHY 423 



side by side with systematic and floristic work. It is another 

 indication of the breadth of his scientific outlook. This re- 

 vealed itself later in the lively sympathy which he showed 

 in the anatomical and physiological enquiries of younger 

 men. 



But above and beyond all this systematic and morpho- 

 logical work lies Hooker's pursuit of Biological Philosophy. 

 In his hands the former necessarily led onwards to the latter. 

 It is indeed his use of facts rather than the acquisition of them 

 that constitutes his highest title to rank among botanists. He 

 fully grasped that * the battle of the evidences will have to be 

 fought out on the field of Physical Science, and not on that of 

 the Metaphysical.' This was the difficult lesson of the period 

 when Evolution was born, and Hooker learned it early. He 

 cleared his mental outlook from all preconceptions, and worked 

 down to the bed-rock of objective fact. Thus he was able to 

 use his vast and detailed knowledge in advancing along the 

 lines of induction alone towards sound generalisations. These 

 had their very close relation to questions of the mutability of 

 species. That subject was approached by him through the 

 study of Geographical Distribution, in which as we have seen 

 he had at an early age become a leading authority. 



The fame of Sir Joseph Hooker as a Philosophical Biologist 

 rests upon a masterly series of Essays and Addresses. The 

 chief of these were the Introductory Essay to the * Flora 

 Tasmaniae/ dealing with the Antarctic Flora as a whole ; 

 the Essay on the Distribution of Arctic Plants, published in 

 1862 ; the Discourse on Insular Floras in 1866 ; the Presi- 

 dential Address to the British Association at Norwich in 1868 ; 

 his Address at York, in 1881, on Geographical Distribution ; 

 and finally, the Essay on the Vegetation of India, published 

 in 1904. None of these were mere inspirations of the moment. 

 They were the outcome of arduous journeys to observe and to 

 collect, and subsequently of careful analysis of the specimens 

 and of the facts. The dates of publication bear this out. 

 The Essay on the Antarctic Flora appeared about twenty 

 years after the completion of the voyage. The Essay on the 

 Vegetation of India was not published till more than half a 



