August 26, 1904.] 



SCIENCE. 



263 



tion. Their plain message is disbelieved, 

 and the investigating judge does not pause 

 until a confession in harmony with his 

 preconceived ideas has, if possible, been 

 wrung from their reluctant evidence. 



This proceeding needs neither explana- 

 tion nor defence in those eases where there 

 is an apparent contradiction between the 

 utterances of experience in different con- 

 nections. Such contradictions must of 

 course be reconciled, and science can not 

 rest until the reconciliation is effected. The 

 difficulty really arises when experience ap- 

 parently says one thing and scientific in- 

 stinct persists in saying another. Two such 

 cases I have already mentioned ; others will 

 easily be found by those who care to seek. 

 What is the origin of this instinct, and 

 what its value ; whether it be a mere prej- 

 udice to be brushed aside, or a clue which 

 no wise man would disdain to follow, I can 

 not now discuss. For other questions there 

 are, not new, yet raised in an acute form 

 by these most modern views of matter, on 

 which I would ask your indulgent atten- 

 tion for yet a few moments. 



That these new views diverge violently 

 from those suggested by ordinary observa- 

 tion is plain enough. No scientific educa- 

 tion is likely to make us, in our unreflective 

 moments, regard the solid earth on which 

 we stand, or the organized bodies with 

 which our terrestrial fate is so intimately 

 bound up, as consisting AvhoUy of electric 

 monads very sparsely scattered through the 

 spaces which these fragments of matter are, 

 by a violent metaphor, described as 'oc- 

 cupying.' Not less plain is it that an 

 almost equal divergence is to be found be- 

 tween these new theories and that modifi- 

 cation of the common-sense view of matter 

 with which science has in the main been 

 content to work. 



What was this modification of common 

 sense? It is roughly indicated by an old 

 philosophic distinction drawn between what 



were called the 'primary' and the 'second- 

 ary' qualities of matter. The primary 

 qualities, such as shape and mass, were 

 supposed to possess an existence quite in- 

 dependent of the observer; and so far the 

 theory agreed with common sense. The 

 secondary qualities, on the other hand, 

 such as warmth and color, were thought to 

 have no such independent existence, being, 

 indeed, no more than the resultants due to 

 the action of the primary qualities on our 

 organs of sense-perception; and here, no 

 doubt, common sense and theory parted 

 company. 



You need not fear that I am going to 

 drag you into the controversies with which 

 this theory is historically connected. They 

 have left abiding traces on more than one 

 system of philosophy. They are not yet 

 solved. In the course of them the very 

 possibility of an independent physical uni- 

 verse has seemed to melt away under the 

 solvent powers of critical analysis. But 

 with all this I am not now concerned. I 

 do not propose to ask what proof we have 

 that an external world exists, or how, if it 

 does exist, we are able to obtain cognisance 

 of it. These may be questions very proper 

 to be asked by philosophy ; but they are not 

 proper questions to be asked by science. 

 For, logically, they are antecedent to sci- 

 ence, and we must reject the sceptical ans- 

 wers to both of them before physical sci- 

 ence becomes possible at all. My present 

 purpose requires me to do no more than 

 observe that, be this theory of the primary 

 and secondary qualities of matter good or 

 bad, it is the one on which science has in 

 the main proceeded. It was with matter 

 thus conceived that Newton experimented. 

 To it he applied his laws of motion; of it 

 he predicated universal gravitation. Nor 

 was the case greatly altered when science 

 became as much preoccupied with the move- 

 ments of molecules as it was with those of 

 planets. For molecules and atoms, what- 



