Hume uses three speakers to present various approaches to reasoning. Cleanthes, Philo, and Demea are the three speakers in Hume's Dialogues Concerning Natural Religion that are offered up to readers as distinct and contrasting approaches to the art of reasoning and knowledge. There is Cleanthes that has his "careful philosophical methods" contrasted by "the causal skepticism of Philo" and "with the rigid inflexible orthodoxy of Demea."

Demea begins by explaining his personal approach to knowledge through the example of how he raised and educated his own children. He based his children and his own reasoning and education upon the saying "Students of philosophy ought first to learn logic, then ethics, next physics, last of all the nature of gods." He went on to explain that in order to understand such a complex concept such as the science of natural theology, one must posses a mature judgment. He does...