Chapter 2, Part 6F - Lieh Tzu

In remote antiquity, there were men of divine enlightenment who were perfectly acquainted with the feelings and habits of all living things, and thoroughly understood the languages of the various species. They brought them together, trained them, and admitted them to their society, exactly like human beings.These sages declared that, in mind and understanding, there was no wide gulf between any of the living species endowed with blood and breath.

And therefore, knowing that this was so, they omitted nothing from their course of training and instruction.
~ Lionel Giles translation via Terebess Asia Online ~

Go here to read the introductory post to the chapters of the Book of Lieh Tzu.