24 ON THE TRUE CLAIMS TO ATTENTION 
transactions, and who have specially manifested practical knowledge 
and skill ; that others of them with great intelligence and sagacity, 
whilst free from the personal interests that may be conceived some- 
times to warp the judgment, have had most eminent opportunities 
from intercourse with practical men in different countries and in 
different pursuits, of collecting the opinions best worth consideration, 
so as really to know much more of business transactions, and what . 
affects them, than any ordinary merchant, manufacturer or dealer, 
however careful an observer within his own sphere, can pretend to ; 
but it may be better to ask what is meant by theory, and what are 
its relations to every branch of human knowledge? Detached facts 
are of little use, and if conjectural relations among them are sup- 
posed, these constitute only an hypothesis, which may be useful in 
guiding further research, but can seldom be relied upon with any 
confidence. As knowledge increases we obtain, as the result of ob- 
servation and reasoning, general expressions, forming principles or 
laws which show us in relation to the subject in hand what may be 
expected in certain circumstances—what consequents must attend 
given antecedents. These collected and arranged constitute the 
theory of the subject, and it is difficult to conceive how it can be 
otherwise than the proper and only safe guide to practice. It is 
quite true that the actual business of life often requires a union of 
considerations drawn from several different kinds of knowledge, and 
if a man studies one of them in his closet and applies its theories 
without regard for other branches equally necessary, he may make 
gross blunders, and you might possibly express their source by call- 
ing him a mere theorist ; but is this any reproach to sound theory, 
or any proof that it is useless, or that we could do without it? A 
practical man is understood to mean one who has been placed, by 
circumstances, in a certain employment, and has acquired a certain 
facility in performing what it demands. From mere constant atten- 
tion to an operation, with the desire to save himself trouble or 
increase his gains he may effect improvements, but not unfrequently 
attachment to the method he first learned, and the force of habit pre- 
vent his appreciating real improvements, and his attention is very 
apt to be confined to the routine of his own business, and to means 
of promoting his own immediate advantage, without extended inquiry, 
enlarged views, or fair consideration of the effect of what he desires 
on others. The practical man, as such, is not then precisely the 
