Full Idea
As Kant saw it, analytic knowledge is possible only in the presence of conceptual complexity, but it should have been clear that simple concepts, unaided by intuition, are as apt as their complex counterparts to act as grounds of a priori knowledge.
Gist of Idea
For Kant analytic knowledge needs complex concepts, but the a priori can rest on the simple
Source
comment on Immanuel Kant (Critique of Pure Reason [1781]) by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 1 'Analyt'
Book Reference
Coffa,J.Alberto: 'The Semantic Tradition from Kant to Carnap' [CUP 1993], p.20
A Reaction
The point is that the concept must 'contain' something for Kant's account of what is analytic. This seems to be a very important thought for those who think the a priori is entirely analytic.