"It is worth emphasizing here that these remarks on the skeptical, relativistic conclusions of empiricism regarding the possibility of prediction also fully apply to Popperianism. Popper, with great self-assurance, claims to have solved—through adopting his falsificationist methodology—the Humean problem of induction and thereby to have reestablished science as a rational enterprise. (See in particular Karl R. Popper, Objective Knowledge, Oxford, England: Oxford University Press, 1972, p.85ff.)
Alas, this is simply an illusion. For how can it be possible to relate two or more observational experiences, even if they concern the relations between things that are perceived to be the same or similar, as falsifying (or confirming) each other, rather than merely neutrally record them as one experience here and one experience here, one repetitive of another or not, and leaving it at that (i.e., regarding them as logically incommensurable) unless one presupposed the existence of time-invariantly operating causes? Only if the existence of such time-invariantly operating causes could be assumed would there by any logically compelling reason to regard them as commensurable and as falsifying or confirming each other.
However, Popper, like all empiricists, denies that any such assumption can be given an a priori defense (there are for him no such things as a priori true propositions about reality such as the causality principle would have to be) and is itself merely hypothetical. Yet clearly, if the possibility of constantly operating causes as such is only a hypothetical one, then it can hardly be claimed, as Popper does, that any particular predictive hypothesis could ever be falsified or confirmed. For then the falsification (or confirmation) would have to be considered a hypothetical one: any predictive hypothesis would only under go tests whose status as tests were themselves hypothetical. And hence one would be right back in the muddy midst of skepticism.
Only if the causality principle as such could be unconditionally established as true, could any particular causal hypothesis ever be testable, and the outcome of a test provide rational grounds for deciding whether or not to uphold a given hypothesis.”
"…It is not difficult to detect that both a priori axioms—of action and argumentation—are intimately related. On the one hand, actions are more fundamental than argumentations with whose existence the idea of validity emerges, as argumentation is only a subclass of action. On the other hand, to recognize what has just been recognized regarding action and argumentation and their relation to each other requires argumentation, and so, in this sense, argumentation must be considered more fundamental than action: without argumentation nothing could be said to be-known about action. But then, as it is in argumentation that the insight is revealed that—while it might not be known to be so prior to any argumentation—in fact the possibility of argumentation presupposes action in that validity claims can only be explicitly discussed in the course of an argumentation if the individuals doing so already know what it means to act and to have knowledge implied in action—both the meaning of action in general and argumentation in particular must be thought of as logically necessary interwoven strands of a priori knowledge.
What this insight into the interrelation between the a priori of action and the a priori of argumentation suggests is the following:
- Traditionally, the task of epistemology has been conceived of as that of formulating what can be known to be true a priori and also what can be known a priori not to be the subject of a priori knowledge. Recognizing, as we have just done, that knowledge claims are raised and decided upon in the course of argumentation and that this is undeniably so, one can now reconstruct the task of epistemology more precisely as that of formulating those propositions which are argumentatively indisputable in that their truth is already implied in the very fact of making one’s argument and so cannot be denied argumentatively; and to delineate the range of such a priori knowledge from the realm of propositions whose validity cannot be established in this way but require additional, contingent in formation for their validation, or that cannot be validated at all and so are mere metaphysical statements in the pejorative sense of the term metaphysical.
Yet what is implied in the very fact of arguing? It is to this question that our insight into the inextricable interconnection between the a priori of argumentation and that of action provides an answer:
- On a very general level, it cannot be denied argumentatively that argumentation presupposes action and that arguments, and the knowledge embodied in them, are those of actors. And more specifically it cannot then be denied that knowledge itself is a category of action; that the structure of knowledge must be constrained by the peculiar function which knowledge fulfills with in the framework of action categories; and that the existence of such structural constraints can never be disproved by any knowledge whatsoever.
It is in this sense that the insights contained in praxeology must be regarded as providing the foundations of epistemology. Knowledge is a category quite distinct from those that I have explained earlier—from ends and means. The ends which we strive to attain through our actions, and the means which we employ in order to do so, are both scarce values. The values attached to our goals are subject to consumption and are exterminated and destroyed in consumption and thus must forever be produced a new. And the means employed must be economized, too. Not so, however, with respect to knowledge—regardless of whether one considers it a means or an end in itself. Of course, the acquisition of knowledge requires scarce means—at least one’s body and time. Yet once knowledge is acquired, it is no longer scarce. It can neither be consumed, no rare the services that it can render as a means subject to depletion. Once there, it is an inexhaustible resource and incorporates an everlasting value provided that it is not simply forgotten. Yet knowledge is not a free good in the same sense that air, under normal circumstances, is a free good. Instead, it is a category of action.
It is not only a mental ingredient of each and every action, quite unlike air, but more importantly; knowledge, and not air, is subject to validation, which is to say that it must prove to fulfill a positive function for an actor within the invariant constraints of the categorical framework of actions. It is the task of epistemology to clarify what these constraints are and what one can thus know about the structure of knowledge as such.
While such recognition of the praxeological constraints on the structure of knowledge might not immediately strike one as in itself of great significance, it does have some highly important implications.”
"In fact, the reason why the social and economic future cannot be regarded as entirely and absolutely uncertain should not be too hard to understand: The impossibility of causal predictions in the field of action was proven by means of an a priori argument. And this argument incorporated a priori true knowledge about actions as such: that they cannot be conceived of as governed by time-invariantly operating causes.
Thus, while economic forecasting will indeed always be a systematically unteachable art, it is at the same time true that all economic forecasts must be thought of as being constrained by the existence of a priori knowledge about actions as such.  Take, for example, the quantity theory of money the praxeological proposition that if you in crease the quantity of money and the demand for money stays constant, then the purchasing power of money will fall.
Our a priori knowledge about actions as such informs us that it is impossible to predict scientifically whether or not the quantity of money will be increased, decreased or left unchanged. Nor is it possible to predict scientifically whether or not, regardless of what happens to the quantity of money, the demand for money to be held in cash balances will go up or down or stay the same. We cannot claim to be able to predict such things because we cannot predict future states of knowledge of people. And yet these states evidently influence what happens with respect to the quantity of money and the demand for money. Then, our theory, our praxeological knowledge incorporated in the quantity theory, has a rather limited usefulness for one’s business of predicting the economic future.”
-  The former Austrian and neo-historicist-hermeneutician-nihilist Ludwig Lachmann, who repeats ad nauseam the unpredictability of future states of knowledge (see his “From Mises to Shackle: An Essay on Austrian Economics and the Kaleidic Society,” Journal of Economic Literature 54 (1976); The Market as an Economic Process (New York: Basil Blackwell, 1986), entirely misses recognizing this latter point. In fact, his arguments are simply self-defeating. For evidently he claims to know for certain the unknowability of future knowledge and, by logical extension, of actions. Yet then he does know something about future knowledge and action. He must know something about knowledge and action as such. And this, precisely, is what praxeology claims to be: knowledge regarding actions as such, and (as I have explained in my “On Praxeology and the Praxeological Foundations of Epistemology and Ethics,” p.49 below) knowledge about the structure which any future knowledge must have by virtue of the fact that it invariably must be knowledge of actors.
"It is certainly not psychologically evident that with every action an actor pursues a goal; and that whatever the goal may be, the fact that it was pursued by an actor reveals that he must have placed a relatively higher value on it than on any other goal of action that he could think of at the start of his action.
It is not evident that in order to achieve his most highly valued goal an actor must interfere or decide not to interfere—which, of course, is also an intentional interference—at an earlier point in time in order to produce a later result; nor is it obvious that such interferences invariably imply the employment of some scarce means—at least those of the actor’s body, its standing room, and the time absorbed by the action.
It is not self-evident that these means, then, must also have value for an actor—a value derived from that of the goal—because the actor must regard their employment as necessary in order to effectively achieve the goal; and that actions can only be performed sequentially, always involving a choice, i.e., taking up that one course of action which at some given time promises the most highly valued results to the actor and excluding at the same time the pursual of other, less highly valued goals.
It is not automatically clear that as a consequence of having to choose and give preference to one goal over another—of not being able to realize all goals simultaneously—each and every action implies the incurrence of costs, i.e., forsaking the value attached to the most highly ranking alternative goal that cannot be realized or whose realization must be deferred, because the means necessary to attain it are bound up in the production of another, even more highly valued goal.
And lastly, it is not evident that at its starting point every goal of action must be considered worth more to the actor than its cost and capable of yielding a profit, i.e., a result whose value is ranked higher than that of the foregone opportunity, and yet that every action is also invariably threatened by the possibility of a loss if an actor finds, in retrospect, that contrary to his expectations the actually achieved result in fact has a lower value than the relinquished alternative would have had.”
"In order to do so, Mises notices in accordance with the strictures traditionally formulated by rationalist philosophers, economic propositions must fulfill two requirements:
- First, it must be possible to demonstrate that they are not derived from observational evidence, for observational evidence can only reveal things as they happen to be; there is no thing in it that would indicate why things must be the way they are. Instead, economic propositions must be shown to be grounded in reflective cognition, in our understanding of ourselves as knowing subjects.
- And secondly, this reflective understanding must yield certain propositions as self-evident material axioms. Not in the sense that such axioms would have to be self-evident in a psychological sense, that is, that one would have to be immediately aware of them or that their truth depends on a psychological feeling of conviction.
On the contrary like Kant before him, Mises very much stresses the fact that it is usually much more pain staking to discover such axioms than it is to discover some observational truth such as that the leaves of trees are green or that I am 6 foot 2 inches.”
— Hans-Hermann Hoppe
It’s a rare few who read, understand and fully appreciate ESAM. For those who already have a solid grasp of the literature I cannot recommend it enough. Those that do accept the challenge often cannot help but marvel at just how important and cutting edge this body of knowledge — praxeology — really is.
Essentially your comment touches upon what this blog is partially about — planting seeds. Further to this will follow several recent remarks and quotes that expand upon the above over the next few days.
Kant, in the course of his critique of classical empiricism, in particular that of David Hume, developed the idea that all our propositions can be classified in a two-fold way:
- On the one hand they are either analytic or synthetic,
- and on the other they are either a priori or a posteriori.
The meaning of these distinctions is, in short, the following. Propositions are analytic when ever the means of formal logic are sufficient in order to find out whether they are true or not; otherwise propositions are synthetic ones. And propositions are a posteriori whenever observations are necessary in order to establish their truth or at least confirm them. If observations are not necessary then propositions are a priori.
The characteristic mark of Kantian philosophy is the claim that true a priori synthetic propositions exist—and it is because Mises subscribes to this claim that he can be called a Kantian. Synthetic a priori propositions are those whose truth-value can be definitely established, even though in order to do so the means of formal logic are not sufficient (while, of course, necessary) and observations are unnecessary.
According to Kant, mathematics and geometry provide examples of true a priori synthetic propositions. Yet he also thinks that a proposition such as the general principle of causality—i.e.,the statement that there are time-invariantly operating causes, and every event is embedded into a network of such causes—is a true synthetic a priori proposition. I cannot go in to great detail here to explain how Kant justifies this view. A few remarks will have to suffice. First, how is the truth of such propositions derived, if formal logic is not sufficient and observations are unnecessary?
In explicitly understanding knowledge as displayed in argumentation as a peculiar category of action, it becomes clear immediately why the perennial rationalist claim that the laws of logic—beginning here with the most fundamental ones, i.e., of propositional logic and of Junctors (“and,” “or,” “if-then,” “not”) and Quantors (“there is,” “all,” “some”)—are a priori true propositions about reality and not mere verbal stipulations regarding the transformation rules of arbitrarily chosen signs, as empiricist-formalists would have it, is indeed correct. They are as much laws of thinking as of reality; because they are laws that have their ultimate foundation in action and could not be undone by any actor. In each and every action, an actor identifies some specific situation and categorizes it one way rather than another in order to be able to make a choice. It is this which ultimately explains the structure of even the most elementary propositions (like “Socrates is a man”) consisting of a proper name or some identifying expression for the naming or identifying of something, and a predicate to assert or deny some specific property of the named or identified object; and which explains the cornerstones of logic: the laws of identity and contradiction. And it is this universal feature of action and choosing which also explains our understanding of the categories “there is,” “all” and, by implication, “some,” as well as “and,” “or,” “if-then” and “not.”
One can say, of course, that something can be “a” and “non-a” at the same time, or that “and” means this rather than something else. But one cannot undo the law of contradiction; and one cannot undo the real definition of “and.” For simply by virtue of acting with a physical body in physical space we invariably affirm the law of contradiction and invariably display our true constructive knowledge of the meaning of “and” and “or.”
— Hans-Hermann Hoppe, Economic Science and the Austrian Method, On Praxeology and the Praxeological Foundation of Epistemology, III, pg 71.
-  On rationalist interpretations of logic see Blanshard, Reason and Analysis, chapters 6, 10; P. Lorenzen, Einfuhrung in die operative Logik und Mathematik (Frankfun/M.: Akademische Verlagsgesellschaft, 1970); K. Lorenz, Elemente der Sprachkritik (Frankfurt/M.: Suhrkamp, 1970); idem, “Diedialogische Rechtfertigung der effektiven Logik,” in: E Kambartel and J. Mittelstrass, eds., Zum normativen Fundament der Wissenschaft (Frankfurt/M.: Athenaum, 1973).
- On the propositional character of language and experience, in particular, see W. Kamlah and P. Lorenzen, Logische Propiideutik, chapter 1; P. Lorenzen, Normative Logic and Ethics, chapter 1. Lorenzen writes:
"I call a usage a convention if I know of another usage which I could accept instead… However, I do not know of another behavior which could replace the use of elementary sentences. If I did not accept proper names and predicators, I would not know how to speak at all… . Each proper name is a convention … but to use proper names at all is not a convention: it is a unique pattern of linguistic behavior. Therefore, I am going to call it ‘logical’. The same is true with predicators. Each predicator is a convention. This is shown by the existence of more than one natural language. But all languages use predicators" (ibid., p. 16). See also J. Mittelstrass, "Die Wiederkehr des Gleichen," Ratio (1966).
- On the law of identity and contradiction, in particular, see B. Blanshard, Reason and Analysis, pp. 276ff, 423ff. On a critical evaluation of 3- or more-valued logics as either meaningless symbolic formalisms or as logically presupposing an understanding of the traditional two-valued logic see W Stegmiiller, HauptstrOmungen der Gegenwartsphilosophie vol. 2 (Stuttgart: Kroner, 1975), pp. 182-91; B. Blanshard, Reason and Analysis, pp. 269-75. Regarding, for instance, the many-valued or open-textured logic, proposed by E Waismann, Blanshard notes:
"We can only agree with Dr. Waismann-and with Hegel-that the black-and-white distinctions of formal logic are quite inadequate to living thought. But why should one say, as Dr. Waismann does, that in adopting a more differentiated logic one is adopting an alternative system which is incompatible with black-and-white logic? What he has actually done is to recognize a number of gradations within the older meaning of the word ‘not’. We do not doubt that such gradations are there, and indeed as many more as he cares to distinguish. But a refinement of the older logic is not an abandonment of it. It is still true that the colour I saw yesterday was either a determinate shade of yellow or not, even though the ‘not’ may cover a multitude of approximations, and even though I shall never know which was the shade I saw" (ibid., pp. 273-74).
Praxeology says that all economic propositions which claim to be true must be shown to be deducible by means of formal logic from the incontestably true material knowledge regarding the meaning of action. Specifically, all economic reasoning consists of the following:
- an understanding of the categories of action and the meaning of a change occurring in such things as values, preferences, knowledge, means, costs, etc;
- a description of a world in which the categories of action assume concrete meaning, where definite people are identified as actors with definite objects specified as their means of action, with some definite goals identified as values and definite things specified as costs. Such description could be one of a Robinson Crusoe world, or a world with more than one actor in which interpersonal relationships are possible; of a world of barter exchange or of money and exchanges that make use of money as a common medium of exchange; of a world of only land, labor, and time as factors of production, or a world with capital products; of a world with perfectly divisible or indivisible, specific or unspecific factors of production; or of a world with diverse social institutions, treating diverse actions as aggression and threatening them with physical punishment, etc; and
- a logical deduction of the consequences which result from the performance of some specified action within this world, or of the consequences which result for a specific actor if this situation is changed in a specified way.
Provided there is no flaw in the process of deduction, the conclusions that such reasoning yield must be valid a priori because their validity would ultimately go back to nothing but the indisputable axiom of action. If the situation and the changes introduced into it are fictional or assumptional (a Robinson Crusoe world, or a world with only indivisible or only completely specific factors of production), then the conclusions are, of course, a priori true only of such a “possible world.” If, on the other hand, the situation and changes can be identified as real, perceived and conceptualized as such by real actors, then the conclusions are a priori true propositions about the world as it really is. 
Such is the idea of economics as praxeology. And such then is the ultimate disagreement that Austrians have with their colleagues: Their pronouncements cannot be deduced from the axiom of action or even stand in clear-cut contradiction to propositions that can be deduced from the axiom of action.
~ Hans-Hermann Hoppe, Economic Science and the Austrian Method, pg 25.
"I would like to challenge the very starting point of the empiricists’ philosophy. There are several conclusive refutations of empiricism. I will show the empiricist distinction between empirical and analytical knowledge to be plainly false and self-contradictory.  That will then lead us to developing the Austrian position on theory, history, and forecasting.
This is empiricism’s central claim: Empirical knowledge must be verifiable or falsifiable by experience; and analytical knowledge, which is not so verifiable or falsifiable, thus cannot contain any empirical knowledge. If this is true, then it is fair to ask: What then is the status of this fundamental statement of empiricism? Evidently it must be either analytical or empirical.
Let us first assume it is analytical. According to the empiricist doctrine, however, an analytical proposition is nothing but scribbles on paper, hot air, entirely void of any meaningful content. It says nothing about anything real. And hence one would have to conclude that empiricism could not even say and mean what it seems to say and mean. Yet if, on the other hand, it says and means what we thought it did all along, then it does inform us about something real. As a matter of fact, it informs us about the fundamental structure of reality. It says that there is nothing in reality that can be known to be one way or another prior to future experiences which may confirm or disconfirm our hypothesis.
And if this meaningful proposition is taken to be analytical, that is, as a statement that does not allow any falsification and whose truth can be established by an analysis of its terms alone, one has no less than a glaring contradiction at hand. Empiricism itself would prove to be nothing but self-defeating nonsense. 
So perhaps we should choose the other available option and declare the fundamental empiricist distinction between empirical and analytical knowledge an empirical statement. But then the empiricist position would no longer carry any weight whatsoever. For if this were done, it would have to be admitted that the proposition—as an empirical one—might well be wrong and that one would be entitled to hear on the basis of what criterion one would have to decide whether or not it was. More decisively, as an empirical proposition, right or wrong, it could only state a historical fact, something like “all heretofore scrutinized propositions fall indeed into the two categories analytical and empirical.” The statement would be entirely irrelevant for determining whether it would be possible to produce propositions that are true a priori and are still empirical ones. Indeed, if empiricism’s central claim were declared an empirical proposition, empiricism would cease altogether to be an epistemology, a logic of science, and would be no more than a completely arbitrary verbal convention of calling certain arbitrary ways of dealing with certain statements certain arbitrary names. Empiricism would be a position void of any justification.
What does this first step in our criticism of empiricism prove? It proves evidently that the empiricist idea of knowledge is wrong, and it proves this by means of a meaningful a priori argument. And in doing this, it shows that the Kantian and Misesian idea of true a priori synthetic propositions is correct.”