You need an intimate friend and a hated enemy
An intimate friend and a hated enemy have always been indispensable requirements for my emotional life; I have always been able to create them anew, and not infrequently my childish ideal has been so closely approached that friend and enemy coincided in the same person.
Yet, certainly, the wise learn many things from their enemies; for caution preserves all things. From a friend you could not learn this, but your foe immediately obliges you to learn it. For example, the states have learned from enemies, and not from friends, to build lofty walls, and to possess ships of war. And this lesson preserves children, house, and possessions.
The present theory then must be considered to be a suggested program or framework for future research and must stand ...
It’s saying no.
That’s your first hint that something’s alive. It says no. That’s how you know a baby is starting to turn into a person. They run around saying no all day, throwing their aliveness at everything to see what it’ll stick to. You can’t say no if you don’t have desires and opinions and wants of your own. You wouldn’t even want to.
No is the heart of thinking.