Full Idea
The having of general ideas is that which puts a perfect distinction betwixt man and brutes.
Gist of Idea
Unlike humans, animals cannot entertain general ideas
Source
John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.11.10)
Book Reference
Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.159
A Reaction
Animals were massively underestimated before the twentieth century. Animals must recognise types of things, as well as individual things. They must register that an individual animal is a dangerous or tasty species. Locke grants them 'some reason'.