Why this theme matters
This theme page collects 6 English passages that touch certainty as a philosophical concern—whether as a concept to define, a value to pursue, or a problem to examine.
In the history of philosophy
Related discussions appear across Greek, Chinese, Indian, Islamic, and modern European traditions. Use the quotations below as entry points, then follow thinker pages for fuller context.
Thinkers in this collection
René Descartes , John Dewey , Voltaire , Al-Ghazali
Frequently asked questions
What did philosophers say about certainty?
They approached certainty from ethics, metaphysics, politics, and lived practice. The passages below show several of those angles in compact form.
Where can I find philosophy quotes about certainty?
This archive page is organized for that search intent: verified English quotations, with links to thinkers and related themes.
How should I read these quotations?
Read the sentence first, then check school and source. A quotation is a doorway into an argument, not a substitute for the surrounding text.