In this passage from Discourse on the Method, Descartes emphasizes the importance of questioning commonly accepted beliefs and customs. By observing that practices which may seem absurd to one group can be accepted as truth by another, he learns not to rely solely on tradition or common consent when forming his beliefs. Instead, Descartes advocates for critical thinking and caution against accepting ideas simply because they are widespread or habitual. This approach allows him to gradually free himself from errors that can obscure our natural intelligence and hinder our ability to reason effectively.