I was just thinking about the 4 personality types, and wonder what their answers might be if they're asked what life is.
It could turn out to be like this:

Choleric:
I don't care. I've said it and I'd say it again, life is black and white.

Phlegmatic:
Let's not differentiate lives...

Melancholic:
Life is not just black and white. It's not just what is and what's not. There are many probabilities. There are many shades of gray..

Sanguine:
Life is not black and white, it's colorful!