The question of free will is whether, an in what sense, rational agents exercise control over their actions and decisions. Addressing this question requires understanding the relationship between freedom and cause, and determining whether the laws of nature are causally deterministic. The various philosophical positions taken differ on whether all events are determined or not—determinism versus indeterminism—and also on whether freedom can coexist with determinism or not—compatibilism versus incompatibilism. So, for instance, hard determinists argue that the universe is deterministic, and that this makes free will impossible.