Full Idea
As a larger amount of water is less easily polluted, so the multitude is less easily corrupted than the few.
Gist of Idea
Like water, large numbers of people are harder to corrupt than a few
Source
Aristotle (Politics [c.332 BCE], 1286a30)
Book Reference
Aristotle: 'Politics', ed/tr. Sinclair,T.A. /Saunders,T. [Penguin 1992], p.222
A Reaction
This was before the arrival of modern mass media, starting with tabloid newspapers. When many people are corrupted, it is much harder for society to recover its sanity.