Full Idea
As proof of the fact that sensible qualities have no real existence he points to the fact that they do not appear the same to all creatures.
Gist of Idea
Sensible qualities can't be real if they appear different to different creatures
Source
report of Democritus (fragments/reports [c.431 BCE], A135) by Theophrastus - On the Senses 63
Book Reference
'The First Philosophers', ed/tr. Waterfield,Robin [OUP 2000], p.179