What was Descartes' initial approach to finding an absolute premise?

Descartes' philosophy is marked by his method of systematic doubt, which he famously articulated in his work "Meditations on First Philosophy." His approach involved beginning with a foundation of skepticism; he sought to question all previously held beliefs and knowledge to determine what could be known for certain. This process led him to eventually conclude that the very act of doubting confirmed his existence ("Cogito, ergo sum" or "I think, therefore I am"). By doubting everything initially, Descartes was able to strip away all assumptions and arrive at the fundamental truths that could withstand scrutiny, ultimately aiming to establish a firm basis for knowledge. This method contrasts sharply with starting with unquestionable beliefs, relying on empirical evidence, or seeking external validation, as these approaches do not embody the fundamental skepticism that Descartes used as a starting point in his philosophical inquiry.