Full Idea
In the case of two drops of water one can completely abstract from all inner difference (of quality and quantity), and it is enough that they be intuited in different places at the same time in order for them to be held to be numerically different.
Gist of Idea
If we ignore differences between water drops, we still distinguish them by their location
Source
Immanuel Kant (Critique of Pure Reason [1781], B319/A263)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.368
A Reaction
Adams points out that this is the same idea as Max Black's famous two spheres thought experiment. We assume that all the water drops are distinct from one another, even if we are unable to perceive the fact. Best explanation.
Related Idea
Idea 14510 Two events might be indiscernible yet distinct, if there was a universe cyclical in time [Adams,RM]