He's Got the Whole World in His Pants

Human agency is the capacity for human beings to make choices and to impose those choices on the world on a collective basis, usually through democratic means. It is normally deployed in contrast to natural forces, which are causes involving only unthinking deterministic processes, but in religion or theology it operates on the basis God helps those who help themselves, in other words the will of God is determined through collective consensus of human beings.

In this it is subtly distinct from the concept of free will, the philosophical doctrine that our choices are not the product of causal chains, but are significantly free or undetermined. Human agency entails the uncontroversial, lower claim that humans do in fact make decisions and enact them on the world. How humans come to make decisions, by free choice or other processes, is not at issue.

Human agency invests a moral component into a given situation. If a situation is the consequence of human decision making, persons may be under a duty to apply value judgements to the consequences of their decisions, and held to be responsible for those decisions. Human agency entitles the observer to ask should this have occurred? in a way that would be nonsensical in circumstances lacking human decisions-makers, for example, the impact of Shoemaker-Levy into Jupiter.

In certain philosophical traditions (particularly those established by Hegel and Marx), human agency is a collective, historical dynamic, more than a function arising out of individuals. Hegel's Geist and Marx's universal class are idealist and materialist expressions of this idea of humans treated as social beings, organized to act in concert.