Algebraic cycles are typically studied by imposing one of several equivalence relations. The equivalence relation most relevant for algebraic K-theory is rational equivalence.

Shepard: Mordin, walk away. Mordin: Can't do that, Shepard. Shepard: I don't have a choice here. Walk away, or I will fire.

I looked out the window and tried to see over the pink rhododendrons and down the block. […] I couldn’t see a thing but a tangle of leathery rhody leaves, and over that, two neighbors standing on the sidewalk talking.

Shestov's Abraham can be seen as one underconcerned with necessity, leaping forward blindly into possibility.