Abstract:
I will present the critique of Kant’s ethics outlined in Part II of Rescuing Autonomy from Kant (Brill, 2023). There I argue that an agent who adopts any of Kant’s formulas of the categorical imperative is committed to a belief in the existence of God (that is, a perfect moral creator), but that Kant offers us no good argument to believe that God exists, and so Kant provides us with no good reason to adopt the categorical imperative. In this talk, I focus on the Formula of the Law of Nature (FLN), the Formula of the End in Itself (FEI), and Kant’s argument from the highest good.
The use of FLN presupposes a belief in the existence of God, because its use rests on a regulative principle of natural teleology known as the principle of suitability (the principle that nothing about an organized being could be bettered in respect of its fitness for purpose). Only a belief in the existence of a perfect moral creator could encourage us to adopt this regulative principle. The derivation of FEI presupposes a belief in the existence of God, because it relies on a regressive argument. The most that a regressive argument from rational nature can show is that a rational agent must regard the end-setting capacity of every rational agent as an end in itself. It cannot show that a rational agent must regard humanity in a person as an end in itself. To complete the derivation of FEI, we must additionally suppose that humanity and personality are coextensive, but the only way that Kant allows us to do so relies on the principle of suitability.
All this would not constitute a fatal problem, if Kant could successfully argue that we have an a priori reason to believe that God exists. But Kant’s argument from the highest good - that we must postulate the existence of God in order to think of the concept of the highest good as possible - is flawed. It is subject to an objection from moral happiness, which says that it is self-contradictory to postulate the existence of God to think of the concept of the highest good as possible, because postulating the existence of God deprives us of moral happiness, which is part of happiness, and thus belongs to Kant’s concept of the highest good.