How did habit shape beliefs according to David Hume?

According to David Hume, habit—or custom—is the fundamental mechanism that shapes our beliefs regarding causality and the uniformity of nature.12

Hume argued that we cannot logically prove that the future will resemble the past or that events are necessarily connected, as these beliefs are not derived from reason or empirical observation. Instead, when we repeatedly experience two events occurring together in a specific sequence, a habitual association is formed in the mind. This mental habit creates a feeling of compulsion or "determination" to expect the second event whenever the first occurs.123

Hume defined belief as a "liveliness" or "vividness" that accompanies an idea. In the process of causal inference, this feeling of being "carried along" by habit infects the idea, transforming it into a belief. Consequently, while these beliefs are not logically justified, they are "inextinguishable propensities of human nature" that are essential for survival, leading Hume to conclude that "custom, not reason, is the great guide of life".12