Four Introductory Lectures on Political Economy

by Nassau William Senior

The same difference separates arts, though the line is less clearly marked. For as every art must use material instruments, it is to a certain extent physical; and as every art aims at producing pleasure or preventing pain, it must be, to a certain extent, mental. Still, however, the difference exists. No one would call rhetoric a physical art, though its teacher must deliver precepts as to voice and gesture. No one would call agriculture a mental art, though a treatise on agriculture would be incomplete which did not compare the advantages and disadvantages of task-work and day-work,—a comparison involving wide and numerous moral considerations.

Where the subject is matter the distinction between an art and a science is in general easily perceptible. No one confounds the science of projectiles with the art of gunnery, or the art of surgery with the science of anatomy. But it appears to be much less easy to distinguish the arts and the sciences which have for their subject the operations of the human mind. Thus we often talk of the art of logic, and of the science of morality. But logic is not an art but a science. It is not a collection of precepts how to reason, but a statement of the principles on which all reasoning depends. The logician does not advise, he merely instructs. He does not teach us to argue by means of syllogisms, but asserts the fact that all reasoning is syllogistic. His statements are all general; they have no relation to time or to place. They are unconnected with any science but his own. On the other hand, morality is not a science but an art. The object of the moralist is not to inform us as to the nature of the faculties and the sensations of man, but to advise us how to use those faculties, and how to subject ourselves to those sensations, for the purpose of promoting our happiness. He must therefore draw his materials from many different sciences, and must vary his precepts according to the social condition of those whom he addresses. The morality of the Stoics was fitted to an aggregate of petty communities constantly engaged in foreign and civil war, in which defeat involved the worst of human evils, the loss of life, of relations, of property, and of liberty. No Greek could be sure that in a year’s time his country might not be conquered by a neighbouring tribe, or his party overthrown by a revolution, and all his family and friends murdered before his eyes, or sold with him into slavery. Under such circumstances, insensibility, the power of enduring the approach and the presence of evil, and the insecurity, and even the absence of good, appeared to be the quality most conducive to happiness. The Stoic moralist, therefore, was as anxious to blunt the desires and harden the perceptions of his pupils, as the English moralist is to rouse their ambition, and to expand their sensibility. The logic of Aristotle and the logic of Whately are the same, but how little do we find in common when we compare the morality of Zeno with that of Smith or of Paley.

It appears to me that the greater tendency to confound science and art, when the subject is mind, than when it is matter, arises from the more immediate influence on human conduct possessed by the mental sciences. The sciences which consider matter have often little apparent connection with any of the arts to which they are subservient. The application of chemistry to agriculture has taken place almost within our own recollection; its application to navigation is still more recent; to transport by land, more recent still; to the transmission of intelligence, scarcely ten years old. Such sciences may be, and indeed generally are, most earnestly studied by men who have no object beyond the discovery and diffusion of truth. That object is enough to satisfy the most ardent scientific ambition, and to urge the most unwearied scientific labours. The astronomer does not consider what will be the practical results of his inquiries, or whether they will lead to any practical results whatever. His object is knowledge. The uses to which that knowledge may be applied, the mode and the degree in which it may affect men’s conduct, he leaves to others.

On the other hand, the mental sciences are directly and obviously connected with the arts of which they furnish the principles; and those arts almost every educated man must practise. No man studies the science of reasoning without resolving to apply its principles whenever he has to exercise the art of controversy. No man inquires into the laws which regulate the human intellect or the human passions, without framing out of them some practical rules for the employment of his own faculties and the regulation of his own affections.

The distinction between physical and mental is important, not only with respect to the subjects treated by the sciences and arts in each class, but also with respect to the principal sources from which they respectively draw their premises.

In all sciences and in all arts these sources are but three—observation, consciousness, and hypothesis. The physical sciences, being only secondarily conversant with mind, draw their premises almost exclusively from observation or hypothesis. Those which treat only of magnitude and number, or, as they are usually called, the pure sciences, draw them altogether from hypothesis. The mathematician does not measure the radii of a circle in order to ascertain that they are all equal: he infers their equality from the definition with which he sets out. Those which abstain from hypothesis depend on observation. It is by observation that the astronomer ascertains the motions of the planets, the botanist classifies plants, and the chemist discovers the affinities of different bodies. They disregard almost entirely the phenomena of consciousness. The physical arts are almost exclusively based on observation. As their object is to produce positive effects, they trust as little as possible to hypothesis; and the mental phenomena which they have to consider are generally few and simple. The art of navigation, the art of mining, or the art of fortification, might be taught by a man who had never studied seriously the operations of his own mind.

On the other hand, the mental sciences and the mental arts draw their premises principally from consciousness. The subjects with which they are chiefly conversant are the workings of the human mind. And the only mind whose workings a man really knows is his own. When he wishes to ascertain the thoughts and the feelings of others, his first impulse always is, to endeavour to suppose himself in what he believes to be their situation, and to consider how he himself would then think and feel. His next impulse is to infer that similar moral and intellectual processes are taking place in them. If he be a cautious observer, he endeavours to correct this inference by examining their countenances, their words, and their actions. But these are uncertain symptoms, often occasioned by a state of mind different from that which they appear to indicate; and often employed for the purpose of concealment or of deception.

When a man endeavours to discover what is passing in the mind of another, by reflecting on what has passed or is passing in his own, the certainty of the result depends of course on the degree in which the two minds coincide. The educated man, therefore, estimates ill the feelings and the faculties of the uneducated, the adult those of the child, the sane those of the insane, the civilised man those of the savage. And this accounts for the constant mismanagement of the lower orders, and of children, madmen, and savages, by their intellectual and moral superiors. The student of mental science is in the situation of an anatomist, allowed to dissect only a single subject, and forced to conjecture the internal conformation of other men by assuming that it resembles that of the subject which he has dissected, and correcting that assumption only by observing the forms of their bones and the outward play of their muscles. The mental peculiarities of other men are likely to mislead him in particular instances. His own mental peculiarities are likely to mislead him on all occasions.

Another important difference, between mental and physical studies, is the degree and the manner in which they respectively can be aided by experiment. When we are dealing with matter, we frequently are able to combine its particles at will, and to ascertain the results of the combination. If we find that, all other things remaining the same, the presence or absence of a given element is followed by the presence or absence of a given result, we ascribe to that element and to that result the relation of cause and effect, or at least of condition and result.

But we can scarcely be said to be able to make experiments on the minds of others. It is necessary to an experiment, that the observer should know accurately the state of the thing observed before the experiment, and its state immediately after it. But when the minds of other men are the subject, we can know but little of either the one state or of the other. We are forced, therefore, to rely not on experiment, but on experience, that is to say, not on combinations of known elements effected for the purpose of testing the result of each different combination, but on our observation of actual occurrences, the results of the combination of numerous elements, only a few of which are within our own knowledge. And the consequence is, that we frequently connect facts which are really independent of one another, and not unfrequently mistake obstacles for causes.