AS PHILOSOPHICAL BIOLOGIST 319 



between Hooker and Darwin, it remains to appraise his own 

 positive contributions to Philosophical Biology. He himself, 

 in his Address as President of the British Association at 

 Norwich in 1868, gives an insight into his early attitude in 

 the enquiry into biological questions. " Having myself," he 

 says, " been a student of Moral Philosophy in a Northern 

 University, I entered on my scientific career full of hopes that 

 Metaphysics would prove a useful mentor, if not a guide in 

 science. I soon found, however, that it availed me nothing, and 

 I long ago arrived at the conclusion so well put by Agassiz, 

 when he says, 'We trust that the time is not distant when it will 

 be universally understood that the battle of the evidences will 

 have to be fought 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. Hooker learned the lesson 

 early. He cleared his mental outlook from all preconceptions, 

 and worked down to the bed-rock of objective fact. Thus he 

 was free 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. The subject was approached by him through the 

 study of geographical distribution, in which, as we have seen, he 

 had at an early age become the 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 Tas- 

 maniae, 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 Presidential 

 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 com- 

 pletion of the voyage. The Essay on the Vegetation of India 



