This post deals with the discipline of Economics as to how Alfred Marshall saw it in 1890. Here are some of the excerpts which i found interesting.
“Economics cannot be compared with the exact physical sciences: for it deals with the ever changing and subtle forces of human nature.”
“It is essential to note that the economist does not claim to measure any affection of the mind in itself, or directly; but only indirectly through its effect.”
“The economist studies mental states rather through their manifestations than in themselves. He estimates the incentives to action by their effects just in the same way as people do in common life.”
“A shilling may measure a greater pleasure (or other satisfaction) at one time than at another even for the same person; because money may be more plentiful with him, or because his sensibility may vary. It would therefore not be safe to say that any two men with the same income derive equal benefit from its use; or that they would suffer equal pain from the same diminution of it.”
“A stronger incentive will be required to induce a person to pay a given price for anything if he is poor than if he is rich. The benefit that is measured in the poorer man’s mind by the cost is greater than that measured by it in the richer man’s mind.”
“Economics takes man just as he is in ordinary life: and in ordinary life people do not weigh beforehand the results of every action, whether the impulses to it come from their higher nature or their lower.”
“Economists study the actions of individuals, but study them in relation to social rather than individual life; and therefore concern themselves but little with personal peculiarities of temper and character. The measurement of motive thus obtained is not indeed perfectly accurate; for if it were, economics would rank with the most advanced of the physical sciences; and not, as it actually does, with the least advanced.”
“It is the business of economics, as of almost every other science, to collect facts, to arrange and interpret them, and to draw inferences from them. “Observation and description, definition and classification are the preparatory activities. But what we desire to reach thereby is a knowledge of the interdependence of economic phenomena…. Induction and deduction are both needed for scientific thought as the right and left foot are both needed for walking.”
Reference