As a noun, it is a feeling of being unsure or not fully believing something. As a verb, it means to question or not fully trust a claim, person, or idea.
From Old French 'doute', from Latin 'dubitum' meaning 'a doubt, question', from 'dubius' meaning 'uncertain'. The silent 'b' comes from the Latin spelling and was reintroduced in English after a period of being dropped. The core sense of uncertainty has remained stable.
The 'b' in 'doubt' is there because scribes wanted to show off its Latin origin; it’s written but never heard. Philosophers sometimes treat doubt not as a weakness but as a tool—something that clears away false beliefs so better ones can grow. In science, organized doubt is called 'skepticism', and it’s a feature, not a bug.
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