Kant's distinction of freedom as transcendental idea and as practical concept: What is the benefit?

Question

Prompted by the current discussion about Kant’s concept of causality of freedom Can Free Will Exist In A Causal Material World? I would like to understand the scope and the difference of the two Kantian concepts

• Freedom as a transcendental idea
• Freedom in its practical sense.

See Critique of Pure Reason (CPR), B561ff. Currently, I understand these two concepts as follows:

An idea is a transcendental idea if it refers to our way to create experience – but not to experience itself. In particular, a transcendental idea lives on the meta-level, it belongs to epistemology.

A concept is practical if it has a normative component, i.e. when the concept considers what should be done. In particular, a practical concepts belongs to ethics.

If you can confirm my understanding of these two concepts, I would like to know – according to Kant

• Why do we need freedom as a transcendental idea?
• Why does freedom in its practical sense explain our experience?

Note. I would wellcome a direct answer, not an invitation to a tour de force through the secondary literature :-)

Answer 1

Now that I see your answer I have a better idea of your question, and would like to attempt a slightly different interpretation.

I do not have the right editions to cite, but am basically looking at Preface to CPR,2E (very helpful), Third Antinomy, and Canon of Pure Reason, Sec. I.

I take it that Kant's main concern is not only Hume's skepticism, but the broader issue of his day: How can a natural causal determinism (the basis of scientific knowledge) be reconciled with freedom (the prerequisite of Protestant morality duty or "practical reason")? He is most concerned with preserving "practical reason" against skepticism, utilitarianism, determinism, atheism, and dogmatic authority. Even if sure knowledge loses out.

First, as to the second part of your question. I think he takes our freedom "in experience" as unproblematic.We can simply observe ourselves as "entities" among phenomena and see that we choose this or that. Moreover, to engage in science and discover "causalities" (efficient or otherwise) also requires speculative freedom. We can insert "spontaneity" into the causal chains to do "experiments." Notably he calls this not some "absolute freedom," but a type of "second causality" to preserve, I believe, its moral imperatives. So our "freedom" is traceable as an uncaused, spontaneous "cause" among sensible things, but not determined by them. Hence moral duties.

Now the difficulty. This tells us nothing about the origins, limits, or demands of this practical, experiential freedom. It is free of efficient "causality" and must therefore originate in the noumenal or transcendental realm. Here it can enjoy "logical relations" apart from temporally "causal relations." Like everything else the will or "soul" has a double existence as phenomenal and as "ding an sich." The problem is, how does Kant know? We presumably have no access to such noumenal entities.

In the Preface, 2E Kant argues that we cannot "know" we have this freedom. We cannot "know" things-in-themselves, such as our soul. But we can still "think" them hypothetically, as long as they are not self-contradicting. So we can deduce this freedom from (1) the observation of experience, (2) the fact that it is not rationally contradicted, and (3) the necessity of some transcendental origin of moral freedom. Such knowledge enables Kant to do what he really wants to do. Which is to makes rational claims about this freedom and practical reason, preserving us from epistemological and moral anarchy.

My understanding is that Kant rewrote this material several times and that nobody, himself included, is entirely satisfied with it. To have his "two causalities" he must separate the phenomenal and noumenal, but must then tell us how he can make claims about the "noumenal" origins of "practical" reason. While I agree with the substance of your criticisms, I am not sure they affect Kant's overall argument. Science can always gain more and more knowledge of cosmological or neural "causes" in the sensible realm. But we can never secure any "final" causes except with regard to moral-practical reasoning.

Answer 2

Thanks to the comments on this site to my question and because of continued reading of Kant’s Critique of Pure Reaons (CPR) I would like to give an answer to my own question.

Why do we need freedom as a transcendental idea – according to Kant?

Kant accepts the thesis of the third antinomy. It states:

Causality according to the law of nature is not the only causality from which all the appearances of the world can be derived. In order to account for theses appearances, it is necessary also to admit another causality, that of freedom. (CPR, B472)

In the proof of this thesis Kant argues: The law of causality which governs experience establishes an infinite chain of causes. But without a first cause each cause of this chain is up in the air and the whole chain does not constitute anything. As a consequence, one has to assume as hypothesis a first cause. It starts the whole chain of causes. The way this first cause acts, is named transcendental freedom (B474).

My short answer: Kant needs the hypothesis of transcencental freedom to accept the law of causality as valid for our experience.

Why does freedom in its practical sense explain our experience – according to Kant?

Kant defines

Freedom, in its practical sense, is the independence of our will from coercion through impulses of sensibility. (CPR B561)

According to Kant, freedom in its practical sense is established by the fact that we can start actions on the base of rational decisions. Also “independent of the necessitation through sensible impulses” (B561) - even against them, I would add. The rational decision initiates a new chain of causality.

The basis of this argumentation is a certain view on human rationality and decision making.

Eventually, I would like to criticize both claims of Kant.

First, Kant’s scope of thinking about causality is too narrow. The only type of causation Kant considers are monocausal linear chains. He does not take into account that a certain effect may presuppose more than one cause. Neither does Kant consider the distinction between necessary and sufficient causes. About which type of causes does Kant speak? Most of all, Kant does not consider cyclic causality in the form of feed-back chains. One can discuss, whether the hypercycle of Manfred Eigen, a model of the interaction of nucleic acids (carrier of information) and amino acids (protein), exemplifies a chain of causality without a first cause.

Of course, one can apply Kant’s argument with linear chains of causality to the standard model of cosmology. Here we must admit: We do not know how the concept of causality applies when extrapolated into the far past. Using this question, one can exemplify the different methods of metaphysics and physics: The former makes the hypothesis of a first cause, the latter leaves the question open for further scientific progress.

Secondly, Kant’s scope of rational decision making is too narrow. Kant considers man primarily as a rational being. For Kant rational mental processes are conscious processes. But most processes in our brain start as unconscious process, not reachable for our introspection.

Up to now we do not have a scientific model about how a decision derives from former experiences, about their evalution and about the unconscious alignment of conflicting alternatives of action. But such models are the subject of current neuroscience, working on a determistic basis. I consider these mechanisms an “ignoramus” but not an “ignorabimus”.