AN INTRODUCTORY LECTURE ON POLITICAL ECONOMY 627 work would raise wages generally merely by causing an increased demand for labour, and independently of more indirect effects '? It may be observed that correct theory on such subjects has a. use beyond its immediate application to practice, a dialectic or controversial use. Those who appeal to theory shah go to that tribunal, even though it is not final. There is here a legitimate sort of argumenturn ad hominem; for which it is not very easy to find a parallel among the older sciences. The state of speculation which still prevails with respect to industry might be illustrated by the science of war upon the following fanciful supposition. Suppose that the authorities of the War Office-or those aspiring to office--were to recommend rules of gunnery, formulm for the flight of projectiles, based upon a theory of gravitation other than the N ewtonian. The simplest method of meeting these proposalsB and estimating the authority of those who made them would be to presen? the true theory of motion in vacuo; though, of course, that theory require? to be modified by complicated corrections for the resistance of the air, before it will ?nable us to hit the mark in practice. The grotesqueness of my illustration brings into view a peculiarity of our study: that in the race of the sciences we are as it were handicapped by having to start at a considerable dis- tance behind the position of mere nescience. An effort is required to remove prejudices worse than ignorance; a great part of the career of our science has consisted in surmounting preliminary fallacies. Now in overcoming these initial obstructions academic train- ing is likely to be of great use. Philosophic culture is calculated to eradicate the weeds of fallacy which grow nowhere so rank as in our field. Indeed many of the difficulties which beset political economy are common to morals and metaphysics. There is a similar inability on the part of those who have been bred in different speculative systems to enter into each other's positions; there is the same vulgar contempt for all speculative systems in uncultivated minds. There is a similar plurality of plausible hypotheses a sort of kaleidoscopic change of views with the turn of the fashion in speculation. For example, just as in morals the theory which resolves virtue into self-interest really accounts for a great part of the phenomena and, leading to by no means the worst sort of conduct, as Bishop Butler shows, has sometimes caused oblivion of an older and a higher theory; so in political economy the theory which explains value by utility--utility in the sense defined by Jevons--has so fascinated s s2
