I think your original question may be answered by understanding that we know our mind exists and that it has a structure because we act on things we deduce through our minds. Read this excerpt from Economic Science and the Austrian Method by Hoppe. This is pp. 8-9 and preceding this was an explanation of Kantian Philosophy of true, synthetic, a priori propositions.

“In all this Mises follows Kant. Yet, as I said earlier, Mises adds one more extremely important insight that Kant had only vaguely glimpsed. It has been a common quarrel with Kantianism that this philosophy [i.e. sythetic a priorism] seemed to imply some sort of idealism. For if, as Kant sees it, true synthetic a priori propositions are propositions about how our mind works and must of necessity work, how can it be explained that such mental categories fit reality? How can it be explained, for instance, that reality conforms to the principle of causality if this principle has to be understood as one to which the operation of our mind must conform? Don’t we have to make the absurd idealistic assumption that this is possible only because reality was actually created by the mind?…

“Mises provides the solution to this challenge. It is true, as Kant says, that true synthetic a priori propositions are grounded in self-evident axioms and that these axioms have to be understood by reflection upon ourselves rather than being in any meaningful sense “observable.” Yet we have to go one step further. We must recognize that such necessary truths are not simply categories of our mind, but that our mind is one of acting persons. Our mental categories have to be understood as ultimately grounded in categories of action. And as soon as this is recognized, all idealistic suggestions immediately disappear. Instead, an epistemology claiming the existence of true synthetic a priori propositions becomes a realistic epistemology. Since it is understood as ultimately grounded in categories of action, the gulf between the mental and the real, outside, physical world is bridged. As categories of action, they must be mental things as much as they are
characteristics of reality. For it is through actions that the mind and reality make contact.”

If you haven’t read “Economic Science and the Austrian Method” I strongly recommend you download the pdf from this website.

To respond to your latest argument, I would have to say that this “given” you speak of is reality. We cannot refute it because it is reality and as Austrian Economics is strongly based in reality we must first consider whether things occur in reality. Could it be proven through reality that superior beings are controlling our minds? By my experience it seems that (A) I control my mind because I can act according to what I judge to do and (B) outside influences affect my mind because my actions may show signs of these outside influences. Notice that in each of these cases, the actions predicate and reveal the workings and influences of the mind. Perhaps you could argue that a superior being influences our mind by creating the innate curiosity and cognizance which distinguishes us from the beasts (since our curiosity and cognizance are shown through actions), but I wonder to what end you argue that we cannot know things innately or that innate ideas may be changed. We must work with what we are given in reality in our minds. Are you perhaps questioning whether reality is true? Because that, I think, is a question entirely unrelated to the question of the mind and synthetic a priorism.

If i were to concede, for sake of argument at least, that we cannot be sure that “The thing controlling our mind might have different innate ideas to us and be playing with us and capable of changing our own innate ideas.” what can we infer from this? I am assuming for a moment that our ability to infer in the first place is not just a delusion.

Is it that we in fact do not know if we are actually delusional and that we really may not be acting, that causation may not be not real, and that the interaction that we think we do with our environment may not be real, and that this discussion we are having might not be what we think it is: you and i engaged in argumentation between ourselves for the purpose of determining if it could in fact be a third party secretly muddling our minds and our ability to act. Could we infer, if inference has any meaning at all in this case, that we may not act, and therefore, as you say, synthetic a priori propositions are a figment of our imaginations?

On the other hand, are we not just pushing back the problem on some hypothetical superior creature or entity that we know must act, even if we cannot? In this case, synthetic a priori propositions must exist after all, even though we all in this realm remain in a semi-delusional state.

The argument is not meaningless. The thing controlling our mind might have different innate ideas to us and be playing with us and capable of changing our own innate ideas.

Something else (the thing controlling my “mind”) can argue that I cannot argue, and leave me helpless to respond having changed/deleted my innate ideas.

Supposing that this thing controlling my “mind” does not exist will not do, for a synthetic a priori truth means apodictic certainty not mere “supposing”.

I’ll give your comments a think!

What you are arguing is that “given” our current innate ideas, we cannot argue against them. I do not disagree with this axiomatic-deductive method. What I am arguing over is what “given” means. There is no way of knowing if there is a superior being putting innate ideas in our mind (Hoppe, Mises, et. al. admit this), therefore we cannot be sure of the truth of synthetic a priori propositions. Hoppe, Rothbard, Mises, et. al. give no argument against the possibility of these superior beings changing our innate ideas.

If you cannot explain this “given” then the deductions are only true “given” that the axiom is. But then it is an analytic rather than synthetic argument, and there are no synthetic a priori truths. There are, of course, synthetic propositions; I am not denying their existence, I am just saying that they might be false.

What we call valid arguments are simply those arguments that are necessarily and indisputably true as determined by rational discussion. No statement about human behavior or experience can be true if when applied to itself is a contradiction. If i say this: “i cannot convey an idea”, you know it is false. No rational person can utter it without knowing it is false from the start. It is a performative contradiction. Now, you can say it, and you can believe it is true, and so can others. But, alas, this doesn’t change the fact that the statement remains irrational, unjustified, invalid, and false.

And we know all this a priori, because it is a performative contradiction.

I find that the statement questioning our minds’ understanding of the body (and its environment), action, causation, means and ends is contradicted in the very act of casting it into doubt. We grasp intellectually, such things as cause and effect and know them to be true a priori. It is because we do that we can interpret our body and reality, and purposefully interfere with reality in order to improve our state. That we presuppose the categories of action in the act of casting them into doubt is to confirm them. In other words, you must necessarily employ the very propositions you doubt, in the act of casting them into doubt.

What do we know about the relationship between our minds and bodies? We know we can use our bodies to interfere with our environment to cause desired effects. We know we can use means to obtain ends. We grasp it intellectually. We know it a priori. And we confirm this a priori knowledge in the very act of argumentation in the pursuit of casting doubt on this knowledge.

I don’t think i have properly grasped the implication you are seeing in the question of who it is exactly who might be controlling the mind.

If the point is that we cannot know if our reason and rational thought can be relied upon because the rug of logic and rational thought can or may be pulled out from under us by this hidden controller, then i’d respond then that A may not be A, and “A is not A” may be true.

However, if that were the case, we are living in chaos or delusion and it would be the height of futility and absurdity to think that you and I or anyone else could logically come to any realistic conclusion about anything. Since all human discussion presupposes the opposite, i consider the possibility ruled out. But perhaps my answer is on a tangent to what you are driving at.

You said that “‘If it is a priori it is not acquired’ is an analytic proposition, not a synthetic one.”

You are saying this is true by definition, that it is a circular argument, a tautology. In other words, it is true a priori, but it doesn’t convey any practical information. But i disagree with your definition. Mine is “if a proposition is true a priori, it cannot be denied without executing a logical inconsistency such as a performative contradiction”. We start with a different definition, so i suppose it is natural that we can’t come to see eye to eye.

“And you could not possibly have acquired it. A priori means prior to experience. Exactly where do you think you acquired it?”

You are equating acquiring something with experiencing it physically. It is not necessary to do this. I once acquired the notion that if 2x+6=0, then x=-3. For a part of my life i had no idea of this, for the rest of my life, after I learned it, i knew it was true a priori. I do not recall ever experiencing algebra like this but on paper and in my mind. Yet i know it is true, a priori and i know i acquired this knowledge at a certain point in my life. It is also not a tautology because algebra is used in practical ways in engineering all the time.

So the synthetic a priori applies and is useful in engineering, praxeology, and now also i do believe, in ethics. Pretty exciting i’d say.

Argumentation ethics is not valid in defending synthetic a priori truths. Like Descartes, Hoppe fails to specify who the arguer is. Of course, it could be a human, as it seems now, but it may also be a being we are not aware of at the moment, but may become aware of later, or have our innate ideas changed (again?) by them. We cannot possible know. Mind and body have a contingent relationship, and that is as far as I’m willing to go. No other position can be defended, and absolutely not with the claim of apodictic certainty.

To me, your comment “If it is a priori it is not acquired”, is certainly an a priori statement itself. It is also, not at all the sort of idea, proposition or concept that is not acquired. I personally, have had to study this subject quite intensely to come to the point where I can tell your statement is of an a priori nature, and I can tell you it is most certainly a concept that I have acquired. Your proposition is therefore also false. But to repeat the most important point about a priori propositions: they are a priori if argumentation implies it; meaning if it is necessarily presupposed in the act of argumentation. It is a priori true if it is impossible to argue it is false, without presupposing it in the first place in the act of arguing it is false.

Knowledge entails truth and only propositions are truth carriers. What then does it mean to say that we have a priori knowledge? Surely, it means that certain propositions are necessarily true by definition and empirical support for them is therefore unnecessary.

What then is the psychology of knowledge? It would seem to be concerned with how we acquire language, learn how to argue, employ deductive logic, etc. It is said by Hoppe that a priori and empirical knowledge are similar psychologically in that both are “acquired, discovered, learned.” If it is a priori it is not acquired. The view of a priori psychologists is that we are genetically predisposed to experience the world in certain ways but these predispositions need “triggering”. So, Chomsky argues, we do not learn language – we learn English. Language is innate but humans need an appropriate linguistic environment for the sophisticated use of language to develop. Chomsky then vacillates between the view that language is innate in the brain, or in the mind! But when we introduce “knowledge” we encounter difficulties because it is an abstract noun. We might say that we are born with the capacity for language, but it is incorrect to say that we know language a priori.

Also, I think it is important to remember, that nominalist’s try not to reify “knowledge” but prefer to talk about the act of knowing (that x is true).

I do not beleive you understand my confusion on the logic of your argument. In all the times you have stated that an innate idea is false, you always assume that being innate has something to do proving the validity of the idea. I am suggesting as has been suggested by Paul that although we might have an innate idea, we first dismiss it on the basis you have laid out, that we don’t know that it is true for sure. However, through a logical process that we would use to determine an a priori true we “re-discover,” if you will, that same idea and find that it is indeed correct. You seem to believe that this is an impossibility and I do not understand why. I hope that makes my confusion a bit more clear.

The logic behind the argument that innate ideas can never be proven true is that they are innate. An innate idea is a premise without foundation: a given. We cannot know what shapes our thoughts, because our thoughts are not yet there.