Thanos: "Little one, it's simple calculus. This universe is finite. If life is left unchecked, life will cease to exist. It needs correcting."
And there the children of the dark Night have their dwellings, Sleep and Death, awful gods. The glowing sun never looks upon them with his beams, neither as he goes up into heaven, nor as he comes down from heaven. And the former of them roam peacefully over the earth and the sea's broad back and is kindly to men; but the other has a heart of iron, and his spirit within him is as pitiless as bronze: whomsoever of men he has onced seized he holds fast; and he is hateful even to the deathless gods.