44 PROGRESS OF SCIENCE IN THE CENTURY. 



Caird spoke as follows : " The history of human 

 knowledge is a history, on the whole, of a continu- 

 ous and ever-accelerating progress. In some of 

 its departments this characteristic may be more 

 marked and capable of easier illustration than in 

 others. External accidents, affecting the history of 

 nations, may often have disturbed or arrested the on- 

 ward movement, or even, for a time, seem to have 

 altogether obliterated the accumulated results of the 

 thought of the past. But on the whole the law is a 

 constant one which constitutes each succeeding age 

 the inheritor of the intellectual wealth of all pre- 

 ceding ages, and makes it its high vocation to hand 

 on the heritage it has received, enriched by its own 

 contributions, to that which comes after. In almost 

 every department of knowledge the modern student 

 begins where innumerable minds have been long at 

 work, and with the results of the observation, the 

 experience, the thought and speculation of the past 

 to help him. If the field of knowledge were limited, 

 this, indeed, would, from one point of view, be a 

 discouraging thought; for we should in that case be 

 only as gleaners coming in at the close of the day 

 to gather up the few scanty ears that had been left, 

 where other labourers had reaped the substantial 

 fruits of the soil. But, so far from that, vast and 

 varied as that body of knowledge which is the result 

 of past research may seem to be, the human race 

 may, without exaggeration, be said to have only en- 

 tered on its labours, to have gathered in only the first 

 fruits of a field which stretches away interminably 

 before it." * 



It is one of the aims of this volume to illustrate 



* A lecture delivered In 1875. Reprinted in Lectures and 

 Addresses, 1899. 



