Full Idea
Kant meant by a 'deduction' not a proof of one proposition from another, but a demonstration of the legitimacy of a concept.
Gist of Idea
For Kant a 'deduction' is not a proof, but the validation of a concept
Source
report of Immanuel Kant (Critique of Pure Reason [1781], 1.1) by Robert Paul Wolff - In Defence of Anarchism 1.1
A Reaction
I assume this leads to Hegel using 'logic' to mean the derivation of the implications of concepts. I can only think that the 'legitimacy' of a concept must refer to the accuracy of its reference. But there are many dimensions to the efficacy of a concept.
Book Reference
Wolff,Robert Paul: 'In Defence of Anarchism' [Harper Torchbooks 1976], p.8