Full Idea
The concept of twelve is by no means already thought merely by my thinking of the unification of seven and five, and no matter how long I analyze my concept of such a possible sum I will still not find twelve in it.
Gist of Idea
No analysis of the sum of seven and five will in itself reveal twelve
Source
Immanuel Kant (Critique of Pure Reason [1781], B015)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.144
A Reaction
I don't find this convincing. All sums can be revealed by analysing the relationships within the sequence of natural numbers.