Another important philosopher of the age was Roger Bacon (c.1214–1294). Bacon was a Franciscan monk who is regarded as a forerunner of the modern scientist. He sought to incorporate the academic disciplines of mathematics and language into theology and philosophy though his book Opus Major.

Bacon proposed that there are three ways to gain knowledge:authority, reason, and experience. He breaks experience into the realms of the internal and external. External experience is awareness of physical reality and the world of the senses. Internal experience is similar to Augustine's “illumination,” a little help from the person upstairs.