Why did Roger Bacon prefer observation to deductive reasoning?

The 13th-century philosopher Roger Bacon preferred observation to deductive reasoning because he believed that experience was essential for achieving certainty in knowledge. While he acknowledged that humans acquire knowledge through both reasoning and experience, he maintained that without the latter, there can be no true certitude.12

Bacon was notably skeptical of the reliance on hearsay and rational deductions common among his contemporaries, holding instead to the superior dependability of confirming experiences. His emphasis on experimentation and the systematic study of nature led him to criticize the methods of other scholars of his day, as he sought to penetrate the secrets of the natural world through positive study rather than through vain speculations or mere scholarly summaries. By prioritizing empirical evidence, Bacon became a major medieval proponent of experimental science, viewing it as a vital tool for understanding the world and confirming faith.32