René Descartes constructs his epistemic visions in his meditations. In Meditation 1, he sets out to shed the false knowledge that was the foundation on which he built his life. If there was any doubt about these core beliefs, he discarded the idea. Descartes demolished his beliefs in Mediation 2 and discovered that it is a thinking thing and because it thinks, it exists. That is, he knew he was at least a mastermind. With Meditation 3, Descartes built the foundations of the previous two meditations and defined substances. First, there are modes that are properties of objects such as greenness, smoothness, cherry flavor. Then he said that there are finite substances which are things like cups, trees and bodies. He also recognized that his mind was a finite substance. God, however, is an infinite substance. Then Descartes moved on to describe formal and objective reality. Formal reality is the reality that has an object. Through this reasoning, modes depend on finite substances and finite substances depend on infinite substances. Objective reality is the reality of the idea that the object has. Through this reasoning the idea of ​​modes depends on the idea of ​​finite substances and the idea of ​​finite substances depends on the idea of ​​infinite substances. Following that logic, Descartes learned that ideas about material things could come from him, but the idea of ​​God, perfect and infinite, could not come from him because he is imperfect and finite. Furthermore, Descartes believed that the idea of ​​God (the highest objective reality) could only come from God, therefore God exists. In Meditation 4 Descartes established that there was no evil demon deceiving him because that being would be imperfect. God, on the other... middle of the paper... saying that all things exist in the mind of God, then the mind of God allows evil to happen in this world. Berkeley said that if God is responsible for evil in Berkeley's idealist view, then God is responsible for evil also from a dualistic view. He claims that the argument that God is responsible for evil is tu quoque, that is, if it's a problem for me, then it's also a problem for you. Berkeley's argument is a red herring and does not refute the original concern that God is responsible for evil. This tactic is a deviation from the original concern that God is responsible for evil and explains absolutely nothing. It probably makes Berkeley's argument weaker due to its failure to explain. In conclusion, I explained Descartes and Berkeley's views on what we can know epistemically, the metaphysical nature of reality, God and how they are related.