Friendship (n.) clears the ground: only friends can lay out a plane of immanence swept clean of idols.
Friendship (n.) among philosophers is a contest: the two friends are claimant and rival for the same thing, and who could tell them apart?
Friendship (n.) in philosophy is not two friends who think together; it is thought itself demanding that the thinker be a friend, so it can split itself and work.
Friendship (n.) after the catastrophe is tinged with weariness and mistrust; brothers and friends can no longer look at each other, or themselves, as before.
Friendship (n.) in a society where any two people share exactly one friend mathematically requires someone who is everyone's friend — the master, the confessor, the doctor: a dictatorship theorem.