Truth seems obvious until you try to define it. The correspondence theory — the most intuitive view — holds that a statement is true if it corresponds to the facts of the world. "Snow is white" is true because snow actually is white. But this raises immediate problems: what exactly are "facts," and how do words connect to reality? These questions have occupied epistemologists for millennia and remain genuinely unresolved.

The coherence theory offers a different account: a belief is true if it coheres — fits consistently — with a broader system of beliefs. Scientists do not test one hypothesis against "bare reality" but against a web of background theories, instruments, and assumptions. This makes truth a matter of internal consistency and mutual support among beliefs. Critics note the problem: a coherent system of false beliefs would count as "true" on this view, which seems wrong.

William James' pragmatic theory holds that true beliefs are those that "work" — that lead to successful action and prediction. If believing that the earth is round helps navigation and science, it is true. This view grounds truth in human practice rather than abstract correspondence. Critics argue it conflates truth with usefulness: a false belief might be useful, while a true belief might have no practical payoff. The pragmatist responds that over the long run, true beliefs tend to be more useful — but this circularity shows the difficulty of the question.