What philosopher believed that only what can be seen clearly and disticntly should be trusted?

The philosopher who believed that only what can be seen clearly and distinctly should be trusted is René Descartes. He emphasized the importance of skepticism and rational doubt in order to arrive at knowledge that is certain and indubitable. Descartes famously stated, "Cogito, ergo sum" ("I think, therefore I am") as the foundation of his epistemology.