Lord Keynes put up two interesting philosophical posts recently. I did want to comment on the first post, which is a good summary of the issues, but haven't had time. However, I did just write up a response to the second about Mises, putting it in historical perspective.
Social Democracy For The 21St Century: A Post Keynesian Perspective
Epistemology and Kinds of KnowledgeWhat is the Epistemological Status of Praxeology and the Action Axiom?Lord Keynes
Mises action principle is Aristotle's every agent acts for an end (telos). Aristotle's approach to biology is teleological. This principle of causality was reiterated by Aquinas and was fundamental to Medieval Scholasticism as rational explanation of articles faith, contra the credo quia absurdam est, misattributed to Tertullian. Long and venerable tradition deeply embedded the principle of causality in the Western psyche.
Hume attacked causality as a principle based on his assumption that knowledge is either from sense data or logic and no sense data correspond to causality other than observation of constant conjunction. Kant attempted to counter this move by moving causality from intellectual intuition to the logical structure of the mind that imposes a necessary connection between cause and effect in structuring knowledge. Aristotle's intellectual intuition of cause (aitia) as a real principle known through intellectual intuition become instead a category inherent to reason that is imposed on knowledge of that which is given in experience.
Not a bad move in retrospect in that it is being borne out somewhat in cognitive research on brain function. But this says nothing about reality outside the mind, which is really Hume's skeptical argument. In Hume's view, humans believe in an external world but know only sense data, which is then structured in terms of logic.
Kant's solution was no escape. It is simply the claim that humans cannot think beyond the bounds of spacial and logical categories — space and time, and existence and causality. The question remains that, although humans are hardwired to think within and in terms of these boundaries, does knowledge correspond actually to reality and do we know this for sure. For Kant it is impossible to know the thing in itself since knowledge as for Hume occurs within the confines of experience, which is structured subjectively. In the attempt to escape Hume, Kant has landed in subjective idealism instead of Aristotle and Aquinas's subjective realism in trying to avoid Hume's skeptical conclusion.
Kant did not realize (and probably could not at the time) that his categories don't always match up with scientific theory and findings. De eloped over a century later, QM and relativity are counter-intuitive, for instance, and suggest that reality is much more complex than the classical world of ordinary thought and observation in which Kant's epistemic categories apply "necessarily". Moreover, there is increasing reason to think that so-called reason cannot be separated from feeling ("passion") categorically, or nature from nurture. There is no "pure reason," anymore than there is an "invisible hand".
In addition, the the Kantian categories function as epistemic substitutes for the metaphysical "essences" that the ancients asserted were intuited intellectually. Hegel realized this in setting forth logic as metaphysics.
Now anthropologists and sociologists are finding that these categories are culturally determined to a far greater degree than previously realized. Philosophy is turing out to be much more anthropological and sociological that Western thinkers had suspected previously. Wittgenstein made use of these anthropological and sociological discoveries in his later work exploring the logic of ordinary language.
The upshot is that Mises generated yet another metaphysical system. Metaphysical systems assume or posit their own criteria, which leads to circular reasoning, or assume unspecified criteria that lead to an infinite regress. This is no ticket to avoiding skepticism, as the failure of metaphysical systems to be universally compelling goes to show.
Scientific method was devised to counter subjectivity, but even science cannot avoid the issue of skepticism since its appeal is to experience and science has not shown how to bridge the gap between the knowing subject and objects of knowledge in that science presumes that immediate knowledge of objects and events is dependent on the senses.
But science makes skepticism a virtue in that scientific theories are general descriptions and general descriptions can only be falsified but never confirmed indubitably if the description is of an open set not all of whose members is known. Nonetheless, the question about the relation of knowledge and reality remains without an answer that is able to overcome skepticism as the view that human knowledge is relational, hence, relative to the knower rather than immediate knowledge of reality independent of the knower. This knowledge is inferred from the inability of the knower to control the known, and this inference depends on the principle of causality, which itself is in question.
Hume was not the first to put forward an argument for skepticism, and his is not the strongest case owing to his flawed assumptions. But he did put the ball in the court of those who wish to claim that there are universally compelling criteria supporting an intrinsic connection between subjectivity and objectivity that yields true knowledge of reality such that it is not influenced by subjectivity, and it is possible to know this for sure, that is, based on adequate criteria.
Mises is stuck in his own mind, which he has confused with reality, and has ruled out empirical testing on the grounds that he matter is settled — he says. No wonder Hayek ran away from that dogmatic claim.
