My theory is that every person contains a certain predetermined essence of either catness or dogness; a rare few contain essences of both. Catness is caution, privacy, order, mind; dogness is impulsiveness, sociability, chaos, body.
Source: wiktionary
For example, every cat is different, but all cats share the same catness because they participate in the cat form.
Source: wiktionary
The cat didn't have a sense of what a witch was, and didn't care, but it was willing to tolerate his catness as long as he maintained proper deference.
Source: wiktionary