Full Idea
Why, when they come into contact, do they [atoms] not coalesce into one, as drops of water run together when drop touches drop?
Gist of Idea
When atoms touch, why don't they coalesce, like water drops?
Source
comment on Democritus (fragments/reports [c.431 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 326a33
Book Reference
Aristotle: 'The Basic Works of Aristotle', ed/tr. McKeon,Richard [Modern Library Classics 2001], p.501
A Reaction
Presumably we must think of atoms as having basic ontological unity, rather than as being little globules of 'stuff'. They are more like monads than they are like mud.