no POPULAR SCIENCE MONTHLY. 



economy, against which in recent times there has been a strong reaction 

 to bring to honor again the factor of observation. It insists that this 

 observation shall not be preliminary only, but that each successive 

 phenomenon shall be tested by it. Price, for instance, is not an abstrac- 

 tion, but a concrete thing, which must be studied before we can have 

 any proper theory of price, and so with all the phenomena of every-day 

 life. The principle of observation applied to the past is the principle 

 of historical research, and as a knowledge of the past is the best key to 

 the understanding of the present, so those who hold this view have 

 engaged in considerable historical researches which have given to their 

 tendencies the name of the historical school. These economists have 

 performed a notable service in pointing out the relativity of economic 

 laws. They have dispelled the notion that the principles of political 

 economy were fixed and immutable and that their activity was necessary 

 to quicken the germ of development which was hidden in the older and 

 more deductive economics. But it will be recognized that they intro- 

 duce no new principles of investigation nor any to which, had they then 

 been formulated, the great writers of earlier days could not have sub- 

 scribed. They have enriched political economy by showing us that 

 the phenomena to be interpreted are far richer and more complex than 

 they appeared to the older economists, but they have not dispensed with 

 the necessity of interpretation, for that is the life blood of the science. 



PSYCHOLOGY. 

 By Professok E. A. PACE, 



CATHOLIC UNIVERSITY OF AMERICA. 



HPO define a priori the nature and scope of a science is always diffi- 

 •*- cult; and it is especially difficult during periods of transition. 

 Speculation as to what psychology ought to be is of course interesting 

 and important ; but its value depends largely upon the frank recognition 

 of what psychology actually is, or perhaps what the psychologies 

 actually are. Even the statement that psychology is the 'science of 

 mental processes/ owes much to its elasticity; for the psychologists who 

 accept it differ as to the meaning of the terms 'mental' and : process.' 

 They differ more widely as to the worth of particular methods and 

 hypotheses: and they are by no means unanimous regarding generaliza- 

 tions and laws. 



This situation is due in part to the fact that psychology, on taking 

 its place in the midst of the empirical sciences, found that these, by 

 their rapid accumulation of data, had both lightened and increased its 

 task. If the way was open io the solution of older problems, it was also 

 beset by new problems which belonged, on one side at least, to phys- 



