The Normativity of Practical Reason

Abstract

One influential form of subjectivism about ethics and value consists in denying the coherence or validity of a certain type of rationally inescapable norm of action. In the terms of a distinction historically associated with the work of Immanuel Kant, this form of subjectivism denies the coherence or validity of so-called categorical imperatives of practical reason, where these are imperatives that apply to agents regardless of their contingently given ends.¹ Thus, when John Mackie claimed to have diagnosed a constitutive error embodied in the prereflective morality of his time, this was because he claimed to have shown that this morality was committed to the validity of something very much like categorical imperatives of practical reason. Thus, Mackie writes:

So far as ethics is concerned, my thesis that there are no objective values is specifically the denial that any … categorically imperative element is objectively valid. The objective values which I am denying would be action-directing absolutely, not contingently … upon the agent’s desires and inclinations. (1977, 29)