Preface 



XI 



believe that he could be dispassionate about 

 anything. His interest in the philosophical basis 

 of his subject was balanced by a close and 

 intimate knowledge of its practical side. He 

 hated and suspected all mutual exclusions, sharp 

 antagonisms, supposed contradictions. Theory and 

 practice were to him as closely connected as good 

 with bad or science with art. He believed there 

 was no such thing as the purely philosophical or 

 purely scientific or purely practical sphere in his 

 subject. He had a passion for gardening and for 

 farming ; he liked to be at work in the soil with 

 the hoe or dung-fork, or amongst the animals on 

 a farm. His thorough knowledge of horticultural 

 processes, which contributed so much to the success 

 of his scientific experiments, was due to his own 

 experience in all the arts of the practical gardener. 

 Digging was an art which he carried to perfection 

 after years of practice. 



His delight in doing things as well as they could 

 be done gave him unusual powers as a teacher. 

 He took an unconcealed pride in his skill in dis- 

 section and in elaborate draughtsmanship. In the 

 laboratory he was always working and learning, and 

 his idea of teaching was not to give information (he 

 often refused it), but to show people how to find 

 out things for themselves. As a lecturer his best 

 qualification was his absorbing interest in the things 

 he had to say. His mind was never more clear, 

 alert, and alive than when he talked to intelligent 

 listeners. He had the instincts of an actor and a 

 good deal of the art ; and he could get in touch 

 with his audience at once. 



