they in any way produce me insofar as I am a thinking thing…” (Descartes 36). Here, he explains that he believes God was the one who created him, not his parents. God allowed for him to have the ability to think and reason, which is why he believes in the existence of God. After coming to the conclusion that he does exist, Descartes attempts to discover how he knows this and continues to use a similar reasoning for how other things that surround him exist. In this meditation, he distinguishes between “objective reality” and “formal reality”. Formal reality is the existence of objects that are outside our perception and is independent of it. The objective reality refers to ideas that we already have inside our minds. According to Descartes, all our ideas already possess a certain degree of objective reality. Each of these ideas has to trace its objective reality back to a source which has as much formal reality as it does objective reality. According to Descartes, this is the case, because an effect can only receive its reality from its cause. By this point, Descartes has already doubted and rejected the belief that there is an external world that resembles the ideas that are already in his mind. He did this because he believes that there is a possibility that he created these ideas out of other ideas which he had about himself. This means that ideas can give rise to other ideas. In order for Descartes to prove that there are other things besides himself that exists, he will have to show that he is not the original source of all of his ideas. He concludes that the only idea that must come from an external force is the idea of God. Descartes mind is limited, and he is unable to come up with the ideas of “omnipotence” or “infinity” by himself. In order for these ideas to have an objective reality in his mind, they must come from an outside force which has an equal or greater degree of formal reality. This source is God himself. This leads Descartes to conclude that our ideas of God are him branding himself into all of our minds.

In St. Thomas Aquinas’s, Summa Theologica, he includes the question as to whether or not God exists. He states, “Because the chief aim of the sacred doctrine is to teach the knowledge of God, not only as He is in Himself, but also as He is the beginning of things and their last end, and especially of rational creature…” (Aquinas 22). The sacred doctrine, or theology, is directed to teach about God’s beliefs and also how he created things, such as ourselves. He divides the topic of God’s existence into 3 articles: “Whether the existence of God is self-evident?”, “whether it can be demonstrated that God exists?”, and “whether God exists?” To the first article, Aquinas responds “ A thing can be self-evident in either of two ways: on the one hand, self-evident in itself, though not to us; on the other, self-evident in itself, and to us” (Aquinas 23). Things can have essence with or without existence. We do not know God’s essence, so he is not self-evident to us, but it can be established by the things that are already self-evident to us. In response to the second article, Aquinas explains that we can establish this by two ways. “One is through cause,and is called ‘a priori,’ and this is to argue from what is prior absolutely. The other is through the effect, and is called a demonstration ‘a posteriori’; this is to argue from what is prior relatively only to us” (Aquinas 25). A priori refers to our knowledge before any experience and a posteriori refers to our knowledge after our experiences. He goes on to explain that if we are more familiar with the effects of something, then we can attempt to find and know the cause as well. An object must always have something that previously existed before it, in order for the object to have been created or derived from the previous one. The effect always follows the cause which is pre-existing. Objects and beings on Earth always have first principles, but how did these first principles come about? Does there need to be a force that initiates change within these things? According to Aquinas, the effects must be proportionate to the causes in order for us to gain knowledge of that specific cause. He states, “Yet from every effect the existence of the cause can be clearly demonstrated, and so we can demonstrate the existence of God from His effects; though from them we cannot perfectly know God as He is in His essence” (Aquinas 26). If God created all things and beings on this Earth, those are the effects and he is the cause of those effects. Since we know the effects, we can demonstrate God’s existence and believe in God’s existence, however we cannot know God. In the third article, the two objections suppose that God does not exist because God is good and if he did exist, there would be no evil in the world but there is evil in the world. Also, not everything in the world must be traced back to being created by God, they could have just been created due to one basic principle, nature. Aquinas responds to these objections with five different arguments. He argues that things in the world are in motion, but something or someone must be able to start the wave of motion. So, he says it is not possible for something