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How does Hume use fire and heat to explain the problem of cause and effect?

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Marble bust of Aristotle with a beard and draped robe, showing detailed facial features and wavy hair, set against a dark background. — Philosophy of science Aristotle, marble portrait bust, Roman copy (2nd century bce) of a Greek original (c. 325 bce); in the Museo Nazionale Romano, Rome.

In the philosophy of science, David Hume uses the example of fire and heat to illustrate the limitations of human knowledge regarding causation and the problem of induction.12

When we observe that fire produces heat, we often assume a "necessary connection" between the two—a belief that fire must, by its nature, cause heat. However, Hume argues that this necessity is not something we actually observe. Through our senses, we only perceive a "constant conjunction": in the past, instances of fire have always been followed by the sensation of heat.1234

Hume contends that we have no rational evidence that this pattern will continue in the future. To claim that fire will cause heat tomorrow simply because it did so in the past requires the assumption that the future will resemble the past—an assumption that cannot be logically justified without circular reasoning. Consequently, Hume concludes that our belief in cause and effect is not a product of reason, but a result of custom and habit, which psychologically compels us to expect the same effects from the same causes.3142