Hi. I’d like to share with you today a footnote from Kant’s Groundwork
for the Metaphysics of Morals.
It comes from near the beginning of the book’s Third Section, titled “Transition from a
Metaphysics of Morals to a Critique of Pure Practical Reason.”
It is in a subsection headed “Freedom Must Be Presupposed as a Property of the Will of
All Rational Beings.”
Here Kant is giving his practical proof of free will, and explaining why he is not attempting
a more rigorous, metaphysical proof.
Kant’s ethical theory does not require him to prove that we are free, only that we cannot
help but act under the idea of freedom, as though we were free.
This is enough to ground his theory, says Kant.
I will read a few sentences from this paragraph, to give you the context, then read the footnote
and explain what I think Kant is saying here.
“It is not enough to prove freedom from certain alleged experiences of human nature
(such a proof is indeed absolutely impossible, and so freedom can be proved only a priori).
Rather, one must show that freedom belongs universally to the activity of rational beings
endowed with a will.
Now I say that every being which cannot act in any way other than under the idea of freedom
is for this very reason free from a practical point of view.
This is to say that for such a being all the laws that are inseparably bound up with freedom
are valid just as much as if the will of such a being could be declared to be free in itself
for reasons that are valid for theoretical philosophy.”
That's where the footnote comes in. Here's what the footnote says:
“I adopt this method of assuming as sufficient for our purpose
that freedom is presupposed merely as an idea by rational beings in their actions in order
that I may avoid the necessity of having to prove freedom from a theoretical point of
view as well.
For even if this latter prob­lem is left unresolved, the same laws that would bind
a being who was really free are valid equally for a being who cannot act otherwise than
under the idea of its own freedom.
Thus we can relieve ourselves of the burden which presses on the theory.”
That's the text of the footnote. So, what does Kant mean by this?
In this subsection he is establishing that all rational beings are free.
(This is a precondition for their being moral.)
But “All rational beings are free” is not the conclusion of an argument proving
that rational beings in themselves possess some property called “freedom.”
Instead, “All rational beings are free” is a necessary assumption that we must make
about the activity of all rational beings, including ourselves.
It’s an assumption that every rational being must make about itself, when it acts.
Kant offers this as a practical proof, and explains in the footnote why he does not attempt
a theoretical or metaphysical proof.
His reasoning is that, in practice, rational beings can never act any other way than “under
the idea of freedom”—we will need to investigate exactly what that means later.
For now, let’s say: we cannot act except with the assumption that our acts are free.
Thus, freedom accompanies every action of ours, just as much as if we knew by some metaphysical
proof that we are free beings.
In the footnote Kant explains his reason for proceeding this way: to avoid the necessity
of giving a theoretical proof of freedom.
Since the same laws of freedom (including moral obligation) that would apply
to beings-that-at-are-free-in-themselves
also apply to beings-that-cannot-act-except-under-the-idea-of-freedom,
Kant can make an end run around the demand
for a metaphysical or empirical proof that humans are free.
If the practical proof works, then it does not matter (for Kantian ethics anyway) whether
we are really free, or really unfree, in some noumenal sense.
So that’s my explanation of what I think Kant is up to in this footnote from page 50
of the Hackett edition of Grounding for the Metaphysics of Morals.
I hope you found it interesting. Thanks for watching today; goodbye.