The Basis of Morality by Part 2 Chapter 6 Page 14

that the specific characteristic of the Categorical Imperative lies in the renunciation of all interest by the Will when acting from a sense of duty. All previous moral principles had thus (he says) broken down, “because the latter invariably attributed to human actions at bottom a certain interest, whether originating in compulsion, or in pleasurable attraction — an interest which might be one's own, or another's” (p. 73; R., p. 62). (Another's: let this be particularly noticed.) “Whereas a universally legislative Will must prescribe actions which are not based on any interest at all, but solely on a feeling of duty.” I beg the reader to think what this really means.

As a matter of fact, nothing less than volition without motive, in other words, effect without cause.