Two actions of an individual are never synchronous; their temporal relation is that of sooner and later. Actions of various individuals can be considered as synchronous only in the light of the physical methods for the measurement of time. Synchronism is a praxeological notion only with regard to the concerted efforts of various acting men.
A man's individual actions succeed one another. They can never be effected at the same instant; they can only follow one another in more or less rapid succession. There are actions which serve several purposes at one blow. It would be misleading to refer to them as a coincidence of various actions.
People have often failed to recognize the meaning of the term "scale of value" and have disregarded the obstacles preventing the assumption of synchronism in the various actions of an individual. They have interpreted a man's various acts as the outcome of a scale of value, independent of these acts and preceding them, and of a previously devised plan whose realization they aim at. The scale of value and the plan to which duration and immutability for a certain period of time were attributed, were hypostatized into the cause and motive of the various individual actions. Synchronism which could not be asserted with regard to various acts was then easily discovered in the scale of value and in the plan. But this overlooks the fact that the scale of value is nothing but a constructed tool of thought. The scale of value manifests itself only in real acting; it can be discerned only from the observation of real acting. It is therefore impermissible to contrast it with real acting and to use it as a yardstick for the appraisal of real actions.
It is no less impermissible to differentiate between rational and allegedly irrational acting on the basis of a comparison of real acting with earlier drafts and plans for future actions. It may be very interesting [p. 103] that yesterday goals were set for today's acting other than those really aimed at today. But yesterday's plans do not provide us with any more objective and nonarbitrary standard for the appraisal of today's real acting than any other ideas and norms.
The attempt has been made to attain the notion of a nonrational action by this reasoning: If a is preferred to b and b to c, logically a should be preferred to c. But if actually c is preferred to a, we are faced with a mode of acting to which we cannot ascribe consistency and rationality. This reasoning disregards the fact that two acts of an individual can never be synchronous. If in one action a is preferred to b and in another action b to c, it is, however short the interval between the two actions may be, not permissible to construct a uniform scale of value in which a precedes b and b precedes c. Nor is it permissible to consider a later third action as coincident with the two previous actions. All that the example proves is that value judgments are not immutable and that therefore a scale of value, which is abstracted from various, necessarily nonsynchronous actions of an individual, may be self-contradictory.
One must not confuse the logical concept of consistency (viz., absence of contradiction) and the praxeological concept of consistency (viz., constancy or clinging to the same principles). Logical consistency has its place only in thinking, constancy has its place only in acting.
Constancy and rationality are entirely different notions. If one's valuations have changed, unremitting faithfulness to the once espoused principles of action merely for the sake of constancy would not be rational but simply stubborn. Only in one respect can acting be constant: in preferring the more valuable to the less valuable. If the valuations change, acting must change also. Faithfulness, under changed conditions, to an old plan would be nonsensical. A logical system must be consistent and free of contradictions because it implies the coexistence of all its parts and theorems. In acting, which is necessarily in the temporal order, there cannot be any question of such consistency. Acting must be suited to purpose, and purposefulness requires adjustment to changing conditions.
Presence of mind is considered a virtue in acting man. A man has presence of mind if he has the ability to think and to adjust his acting [p. 104] so quickly that the interval between the emergence of new conditions and the adaptation of his actions to them becomes as short as possible. If constancy is viewed as faithfulness to a plan once designed without regard to changes in conditions, then presence of mind and quick reaction are the very opposite of constancy.
When the speculator goes to the stock exchange, he may sketch a definite plan for his operations. Whether or not he clings to this plan, his actions are rational also in the sense which those eager to distinguish rational acting from irrational attribute to the term "rational." This speculator in the course of the day may embark upon transactions which an observer, not taking into account the changes occurring in market conditions, will not be able to interpret as the outcome of constant behavior. But the speculator is firm in his intention to make profits and to avoid losses. Accordingly he must adjust his conduct to the change in market conditions and in his own judgment concerning the future development of prices.
However one twists things, one will never succeed in formulating the notion of "irrational" action whose "irrationality" is not founded upon an arbitrary judgment of value. Let us suppose that somebody has chosen to act inconstantly for no other purpose than for the sake of refuting the praxeological assertion that there is no irrational action. What happens here is that a man aims at a peculiar goal, viz., the refutation of a praxeological theorem, and that he accordingly acts differently from what he would have done otherwise. He has chosen an unsuitable means for the refutation of praxeology, that is all. [p. 105]
 In order to avoid any possible misunderstanding it may well be expedient to emphasize that this theorem has nothing at all to do with Einstein's theorem concerning the temporal relation of spatially distant events.
 Cf. Felix Kaufmann, "On the Subject-Matter of Economic Science," Economica, XIII, 390.
 Cf. P.H. Wicksteed, The Common Sense of Political Economy, ed. Robbins (London, 1933), I, 32 ff.; L. Robbins, An Essay on the Nature and Significance of Economic Science (2d ed. London, 1935), pp. 91 ff.
 Plans too, of course, may be self-contradictory. Sometimes their contradictions may be the effect of mistaken judgment.
But sometimes such contradictions may be intentional and serve a definite purpose.
If, for instance, a publicized program of a government or a political party promises high prices to the producers and at the same time low prices to the consumers., the purpose of such an espousal of incompatible goals may be demagogic.
Then the program, the publicized plan, is self-contradictory; but the plan of its authors who wanted to attain a definite end through the endorsement of incompatible aims and their public announcement is free of any contradiction.