David Hume and George Berkeley are two of the most famous philosophers of all time. The key difference between them was their contrasting opinions on the existence of god. Berkeley felt god must exist. Berkeley reasoned this through the following thought experiment: if our insights into the world around us are just perceptions and nothing more then why, Berkeley asked, can’t we just wish them away? Why can’t we change the world around us if it is nothing more than a perception in our physical brains? The answer according to Berkeley is that there is a god which controls our perceptions. Thus there is something greater than the physical make up of our minds.
David Hume was very skeptical about the human ability to know or understand much of anything. Hume felt humans were irrational beings that were controlled by their emotions. Hume disagreed with Berkeley about the existence of god. Hume disagreed because he felt that just because our perceptions could not change the world we perceive does not imply a fixed world; and thus does not imply a god. It simply means, in Hume’s opinion, that our perceptions are limited. Berkeley felt that our subjective minds must prove the existence of god given that our subjective minds are able to perceive things that actually exist. Berkeley felt that only a god could allow such continuity between perception and reality. Hume argued that this perception of reality was just a subjective manipulation of our minds. Hume argued that humans could never prove the existence of god based only on our perceptions of the world. As our perception that we have real perceptions could just be a manipulation of our mind. In contrast Berkeley felt that our understanding of the world must represent a greater power.

Aside from this disagreement the two philosophers had a lot in common. Both were students of John Locke and considered themselves philosophers in the liberal tradition. They both believe that humans had the ability to reason and understand the world. Hume was more pessimistic in this regard, but, both were philosophers of the enlightenment and both believed in the scientific method as a mechanism to discover truth.