 In his Communia naturalium, Bacon explains that he wrote his account of sensation, the sensitive soul, and perception in the Perspectiva as a criticism of the common teaching of the Aristotelian teachers in the schools. Further, he comes to the conclusion in the Opus maius that the greater philosophers in the Greek, Islamic, and Christian traditions maintained that the Agent Intellect is God, the source and agent of illumination. He now makes this position his own, and attacks those teachers who hold that the agent and the potential intellects are parts of the soul.