Praxeology from Wiki
Praxeology
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Praxeology is the science of human action. The term was first coined in 1890 by Alfred Espinas in the Revue Philosophique, but the most common use of the term is in connection with the work of Ludwig von Mises and the Austrian School of economics.
Explanation
Mises attempted to find the conceptual root of economics. Like other Austrian and classical economists, he rejected the use of observation, saying that human actors are too complex to be reduced to their component parts and too self-conscious not to have their behaviour affected by the very act of observation. Observation of human action, or extrapolation from historical data, would thus always be contaminated by overlooked factors in the way that the natural sciences would not be (although in quantum mechanics observation of one property of a system causes uncontrollable changes in other properties).
To counter the subjective nature of the results of historical and statistical analysis (see Methodenstreit), Mises looked at the logical structure of human action (he entitled his magnum opus Human Action). In other works he built on the methodological aspect of Economics, on a PostKantian base, the synthetic a priori.
From praxeology Mises derived the idea that every conscious action is intended to improve a person's satisfaction. He noted that praxeology is not concerned with the individual's definition of end satisfaction, just the way he sought that satisfaction and that individuals will increase their satisfaction by removing sources of dissatisfaction or "uneasiness".
An acting man is defined as one capable of logical thought — to be otherwise would be to make one a mere creature who simply reacts to stimuli by instinct. Similarly an acting man must have a source of dissatisfaction which he believes capable of removing, otherwise he cannot act.
Another conclusion that Mises reached was that decisions are made on an ordinal basis. That is, it is impossible to carry out more than one action at once, the conscious mind being only capable of one decision at a time — even if those decisions can be made in rapid order. Thus man will act to remove the most pressing source of dissatisfaction first and then move to the next most pressing source of dissatisfaction. Additionally, Mises dismissed the notion that subjective values could be calculated mathematically; man can not treat his values with cardinal numbers, e.g., "I prefer owning a television 2.5 times as much as owning a DVD player."
As a person satisfies his first most important goal and after that his second most important goal then his second most important goal is always less important than his first most important goal. Thus, the satisfaction, or utility, that he derives from every further goal attained is less than that from the preceding goal.
In human society many actions will be trading activities where one person regards a possession of another person as more desirable than one of his own possessions, and the other person has a similar higher regard for his colleague's possession than he does for his own. This assertion modifies the classical economic view about exchange, which posits that individuals exchange goods and serves that they both appraise as being equal in value. This subject of praxeology is known as catallactics.
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Added in edit. Forget the last part of the article:
Categories
The categories of praxeology, the general, formal theory of human action, as outlined by Murray Rothbard (pp. 945-946) are as follows:[1]
A. The Theory of the Isolated Individual (Crusoe Economics)
B. The Theory of Voluntary Interpersonal Exchange (Catallactics, or the Economics of the Market)
1. Barter
2. With Medium of Exchange
a. On the Unhampered Market
b. Effects of Violent Intervention with the Market
c. Effects of Violent Abolition of the Market (Socialism)
C. The Theory of War--Hostile Action
D. The Theory of Games (e.g., Von Neumann and Morgenstern)
E. Unknown
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