AIMS, ETC., OF SCIENTIFIC THOUGHT. 181 



means of conceiving such things. But, then, we cannot be sure that 

 the facts will not make us learn to conceive them ; in which case they 

 will cease to be inconceivable. In fact, the putting of limits to human 

 conception must always involve the assumption that our previous ex- 

 perience is universally valid in a theoretical sense ; an assumption 

 which we have already seen reason to reject. Now, you will see that 

 our consideration of this opinion has led us to the true sense of the as- 

 sertion that the order of Nature is reasonable. If you will allow me 

 to define a reasonable question as one which is asked in terms of ideas 

 justified by previous experience, without itself contradicting that ex- 

 perience, then we may say, as the result of our investigation, that to 

 every reasonable question there is an intelligible answer, which either 

 we or posterity may know. 



We have, then, come somehow to the following conclusions : By 

 cientific thought we mean the application of past experience to new 

 circumstances, by means of an observed order of events. By saying 

 that this order of events is exact, we mean that it is exact enough to 

 correct experiments by, but we do not mean that it is theoretically or 

 absolutely exact, because we do not know. The process of inference 

 we found to be in itself an assumption of uniformity, and that, as the 

 known exactness of the uniformity became greater, the stringency of 

 the inference increased. By saying that the order of events is reasona- 

 ble, we do not mean that every thing has a purpose, or that every thing 

 can be explained, or that every thing has a cause ; for neither of these 

 is true. But we mean that to every reasonable question there is an in- 

 telligible answer, which either we or posterity may know by the exer- 

 cise of scientific thought. 



For I especially wish you not to go away with the idea that the 

 exercise of scientific thought is properly confined to the subjects from 

 which my illustrations have been chiefly drawn to-night. When the 

 Roman jurists applied their experience of Roman citizens to dealings 

 between citizens and aliens, showing by the difference of their actions 

 that they regarded the cicumstances as essentially different, they laid 

 the foundations of that great structure which has guided the social 

 progress of Europe. That procedure was an instance of strictly 

 scientific thought. When a poet finds that he has to move a strange 

 new world which his predecessors have not moved ; when, nevertheless, 

 he catches fire from their flashes, arms from their armory, sustentation 

 from their footprints, the procedure by which he applies old experi- 

 ence to new circumstances is nothing greater or less than scientific 

 thought. When the moralist, studying the conditions of society and 

 the ideas of right and wrong: which have come down to us from a time 

 when war was the normal condition of man and success in war the 

 only chance of survival, evolves from them the conditions and ideas 

 which must accompany a time of peace, when the comradeship of 

 equals is the condition of national success the process by which he 



