10 REPORT— 1902. 



potency of all terrestrial life. Bacon in his day said very much the same 

 thing : ' He that will know the properties and proceedings of matter 

 should comprehend in his understanding the sum of all things, which 

 have been, which are, and which shall be, although no knowledge can 

 extend so far as to singular and individual beings.' Tyndall's conclusion 

 was at the time thought to be based on a too insecure projection into the 

 unknown, and some even regarded such an expansion of the crude 

 properties of matter as totally unwarranted. Yet Tyndall was certainly 

 no materialist in the ordinary acceptation of the term. It is true his 

 arguments, like all arguments, wei-e capable of being distorted, especially 

 when taken out of their context, and the address became in this way an 

 easy prey for hostile criticism. The glowing rhetoric that gave charm to 

 his discourse and the poetic similes that clothed the dry bones of his close- 

 woven logic were attacked by a veritable broadside of critical artillery. 

 At the present day these would be considered as only appropriate 

 artistic embellishments, so great is the unconscious change wrought in our 

 surroundings. It must be remembered that, while Tyndall discussed the 

 evolutionary problem from many points of view, he took up the position 

 of a practical disciple of Nature dealing with the known experimental and 

 observational realities of physical inquiry. Thus he accepted as fundamental 

 concepts the atomic theory, together with the capacity of the atom to 

 be the vehicle or repository of energy, and the grand generalisation of the 

 conservation of energy. Without the former, Tyndall doubted whether it 

 would be possible to frame a theory of the material universe ; and as to 

 the latter he recognised its radical significance in that the ultimate 

 philosophical issues therein involved were as yet but dimly seen. That such 

 generalisations are provisionally accepted does not mean that science is 

 not alive to the possibility that what may now be regarded as fundamental 

 may in future be superseded or absorbed by a wider generalisation. It is 

 only the poverty of language and the necessity for compendious expression 

 that oblige the man of science to resort to metaphor and to speak of the 

 Laws of Nature. In reality, he does not pretend to formulate any laws 

 for Nature, since to do so would be to assume a knowledge of the inscru- 

 table cause from which alone such laws could emanate. When he speaks 

 of a ' law of Nature ' he simply indicates a sequence of events which, so far 

 as his experience goes, is invariable, and which therefore enables him to 

 predict, to a certain extent, what will happen in given circumstances. 

 But, however seemingly bold may be the speculation in which he permits 

 himself to indulge, he does not claim for his best hypothesis more than 

 provisional validity. He does not forget that to-morrow may bring a new 

 experience compelling him to recast the hypothesis of to-day. This plas- 

 ticity of scientific thought, depending upon reverent recognition of the 

 vastness of the unknown, is oddly made a matter of reproach by the very 

 people who harp upon the limitations of human knowledge. Yet the 

 essential condition of progress is that we should generalise to the best of 

 our ability from the experience at command, treat our theory as provi- 



