Hume observes that while we may perceive two events that seem to occur in conjunction, there is no way for us to know the nature of their connection. Based on this observation, Hume argues against the very concept of causation, or cause and effect. We often assume that one thing causes another, but it is just as possible that one thing does not cause the other.

Hume claims that causation is a habit of association, a belief that is unfounded and meaningless. Still, he notes that when we repeatedly observe one event following another, our assumption that we are witnessing cause and effect seems logical to us. Hume holds that we have an instinctive belief in causality, rooted in our own biological habits, and that we can neither prove nor discount this belief. However, if we accept our limitations, we can still function without abandoning our assumptions about cause and effect. Religion suggests that the world operates on cause and effect and that there must therefore be a First Cause, namely God. In Hume’s worldview, causation is assumed but ultimately unknowable. We do not know there is a First Cause, or a place for God.