doesn’t the assertion of natural regularity somehow involve a posteriori knowledge?
Yes. As Mises writes in section 4:
The first and basic achievement of thinking is the awareness of constant relations among the external phenomena that affect our senses.
Thinking of the world as posssesing regularity [which means, I now see from reading the book, that there exist A’s and B’s in the world such that A happening always results in B happening, which we decide to call A causes B] is an achievement, meaning you don’t get it for free, it is not innate in you, you achieve it by thinking. Not only that, you acheive it by observing and thinking about the external world. All of which makes it aposteriori.
However, and there is a big however, this acheivement comes very early on, and gets ingrained so deeply in our way of looking at the world that…
-
the negation of what it asserts is unthinkable for the human mind [once it learns this lesson] and appears to it as nonsense.
-
Also, every time we approach any problem whatever, we approach it with the assumption of regularity [AKA reliable causes that produce reliable effects] in the universe [for otherwise there would be no point in trying anything, since its result would be some random thing].
Mises mentions these two things when he writes about causality, the stepchild of regularity:
Whatever philosophers may say about causality, the fact remains that no action could be performed by men not guided by it. Neither can we imagine a mind not aware of the nexus of cause and effect.
But these two things are what really matter, the important features, of a priori knowledge, as Mises writes in section 3.
“If we qualify a concept or a proposition as a priori, we want to say: first, that the negation of what it asserts is unthinkable for the human mind and appears to it as nonsense; secondly, that this a priori concept or proposition is necessarily implied in our mental approach to all the problems concerned, i.e., in our thinking and acting concerning these problems.”
So that, even though regularity is a posteriori to a stickler, Mises is going to go ahead and call it a priori.
He says this explicitly when he writes:
In this sense we may speak of causality as a category or an a priori of thinking and acting.
The phrase “in this sense” always means “not in the full, strict sense of the word, but in a partial sense of the word”.
In parrallel, mustn’t all scientific experimentation involve both a posteriori and a priori truth?
That is exactly the point Mises is trying to get across. The posisvists apparently pride themselves on not using any apriori concepts or assumptions, and being wholly a posteriori. Mises is pointing out that they certainly assume regularity and cause and effect, which is a priori. [Not to mention the rules of logic, such as a thing cannot be both A and not A at the same time. I wonder why he is laying such heavy stress on them using regularity and cause and effect].
So a posteriori does not need to be proven because it only needs to be recorded…
That which is recorded is what we call history. A posteriori knowledge is more than that. It is a knowledge of the future based on the history we have recorded or seen. For example, the sun having risen every day that makind knows about is history. From this history, we gain aposteriori knowledge that the sun will rise tomorrow, too. This kind of knowledge is called induction. Of course it is very shaky philosophically [though I admit this is ignoring Clayton’s assertion that there is some math that can prove it, mainly because of my ignorance of that math], but it works and it’s all we’ve got, really. Again, Mises is pointing out that all a posteriori knowledge has a fat dose of a priori mixed into it, the assumptions of regularity and causality.
This makes the whole priori/posteriori dichotomy confusing to me, since empricist economists always bash a priori methods but isn’t an experiment (even if no economic experiment is possible) also an a priori assertion, if one seeks to use it as a device of prediction?
See the above.
He throws Marx away with the usual deftness, turning his own materialist philosophy against him. If I am right in understanding, the material productive forces alone decide the course of history, that there is no correct or incorrect only the march of history. This of course implies that Marx’s own writings have no significance. Someone correct me if I’m wrong on this.
The way I understand it is this. Say you have an adding machine. When you ask it 2+2= what, it certainly doesn’t decide by itself what the answer is. The builder of the machine set it up in such a way that gives the answer 4. The builder could equally have built it to give the answer 3. In the latter case, of course, the adding machine gives the wrong answer, but of course the machine itself doesn’t know it’s the wrong answer.
Marx was saying that all human beings are adding machines. Whatever they think is determined not by them, but by something outside them [=materal productive forces], which are in this sense the builders of those complex adding machines, people. And since people are subjected to these forces in different ways, they will think differently, like two adding machines that have been built to give different answers to the same question.
Mises has two objections to this. First, that it is ridiculous to assume that material productive forces sit around and think and plan how to build people. He is saying that Marx seemed to be asserting in some of his writings that material productive forces actually do that, that they are sentient beings of some kind that have plans and minds and schemes. He adds that Marx himself retreated somewhat in his later writings from such a ridiculous notion.
There is a second objection Mises raises, one that applies even if we assume that material productive forces are not sentient beings. As long as we still assume that humans think what they think as a result of something outside them [=material productive forces] building them a certain way, then how do humans know what is true or false? How do we know that 2+2 is 4? Maybe it’s really 3, but the material productive forces have molded our minds to mistakenly think it’s 4.
For that matter, how does Marx know that what he wrote is correct? The only reason he thinks it is correct is because the material productive forces acting upon him in a certain way made him think he’s right. But maybe he’s one of those adding machines built to think 2+2=3, and Adam Smith was the one built correctly, who thought capitalism is great stuff?