It is natural that men, who depend on their gifts of mind and conscious skills in the struggle to survive, should put a boundless faith in those powers. That faith is less an inference from observation than an indispensable condition of tolerable, and continuing, existence.#
Freedom to devise constructions is not compatible with the existence of an omni-competent, all-inclusive general theory.#
If we stand back from the claim that explanation and prediction are one, in practice and not merely in principle, we shall surely be impressed with their contrasting nature. To be allowed to taste a cake and be asked what were the ingredients is not the same thing as to be given some ingredients and be asked what can be made of them. #
By a certain paradox, it is the cyclical character of some phenomena which makes possible the temporal location of those events which are singular and non-repetitive.#
Measurement of time requires the assumption that some easily recognizable cycle will repeat itself as long as we need it, together with the willingness to define a unit of duration as the lapse of time required for the cycle to complete itself.#
To claim (as the present writer does) that these questions which can be divorced from considerations of time are essential to our understanding, and the answers to them necessary for full illumination of the economic field, is to say that the field, of its nature, cannot be served by a completely general, undivided theory springing from one sole set of presuppositions. Economics, concerned with thoughts and only secondarily with things, the objects of those thoughts, must be as protean as thought itself. To adopt one rigid frame and appeal exclusively to it is bound to be fatal. It is as though we should draw up a plan of exploration of an unknown country, and rule out any change of that plan, even one suggested by what the explorers actually find.#
The paradox of rationality is that it must concern itself with choosing amongst things fully nown; but in the world of time, only that is fully known which is already beyond the reach of choice, having already become actual and thus knowable.#
What is action but the response to feelings? What action would there be if there were no desires, no consciousness of dissatisfaction, no longing for a ‘good state of mind’? What is motive, except emotion?#
The strength of the timeless system is that it can be self-contained, totally independent of any world outside itself. Any system which exists in time and includes expectation is exposed to the whole conceivable range of non-economic events. For how can we limit the classes of events which can offer suggestions to expectation?#
If the price of any durable or storable good is to remain even briefly at rest, it needs to have attained a level which divides the potential holders of this asset into Bulls and Bears of its price. For if all of them suddenly come to think alike, at that moment the price will change abruptly.#
The prime duty of a theory is to tidy the mind, leaving it clear for practical activity.#
Knowledge and constancy are so intimately related in all science, that we can say that science is merely the recognition and description of constancy.#
That language of ex ante and ex post was the key which released economic theory from its subservience to that conception of time which prevails in celestial mechanics, the time which is a mere dimension where the distinction between past and future is meaningless.#
Time as we seem to experience it has a character profoundly and radically different from that of a mere algebraic abstraction capable of being adequately represented by the symbol of a scalar quantity.#Quoted in Ludwig Lachmann, Capital, Expectations, and the Market Process (1940)