Why did David Hume doubt that people can know anything beyond experience?

David Hume, a central figure of the Scottish Enlightenment, argued that human knowledge is limited to experience because he rejected the possibility of rationally justifying claims about the unobserved world.12

Hume distinguished between "relations of ideas" (such as mathematics) and "matters of fact," which are known only through experience. He famously identified the problem of induction, noting that our beliefs about the future—such as the expectation that the Sun will rise or that fire will produce heat—rely on the assumption that the future will resemble the past. Hume argued that this assumption cannot be proven without circular reasoning, as any attempt to justify it relies on the very principle it seeks to establish.32

Furthermore, Hume observed that we never perceive a "necessary connection" between cause and effect; we only observe a "constant conjunction" of events. Because we cannot rationally establish that nature will remain uniform or that unobserved events must follow past patterns, he concluded that we have no rational basis for knowledge beyond our immediate experience.21