6 PROGRESS OF HUMAN KNOWLEDGE. 



Partial knowledge often perplexes more, and fur- 

 nishes larger material for false philosophy, than does 

 sheer ignorance. Tt is the better understanding of the 

 nature of proof, and the cogent demand for it, which 

 characterise the science of our day. Taking the total 

 circle of human knowledge, we find in this single con- 

 dition the source of all recent progress, and the foun- 

 dation of what is to come. The inductions of ancient 

 philosophy, with rare exceptions, were drawn from 

 evidence at once shallow and incomplete, unchecked 

 by experiment or multiplied observations. The change 

 since made forms a signal step in the intellectual 

 advancement of man. While doubtless due in great 

 part to the rigid demands of physical science, the in- 

 fluence has collaterally extended to other and less de- 

 fined branches of human knowledge. The whole may 

 best be described as a growing demand for Truth, put 

 before us as the end and measure of all evidence, to 

 whatever subject directed. So in a general sense it 

 must ever have been regarded. But the 'Afojdeia 

 seoj/ 6|u,o7ro?u of the ancients was Truth in the clouds, 

 or seen through the mist of vague theories which no 

 right methods of research came in aid to dispel. 



It must be owned, however, that there are still 

 many who live in this cloud-land of imperfect know- 

 ledge and visionary belief. The phantasms of mes- 

 merism, and the still worse follies or frauds of spirit- 

 rapping, table-turning and clairvoyance, often wrapped 

 in the phraseology of real science, deceive not only the 

 many credulous of the world, but even some men who 

 in other matters can justly appreciate the evidence of 



