Little did Descartes know about the influence that his model of epistemology (philosophy of how we obtain knowledge) would have upon the course of philosophy. After Descartes’ rationalism, Locke responded with his own empirical model of epistemology. In response to the later radicalization of Locke’s view, Kant articulated the constructivist view of epistemology.
But of these three primary views, which had the best model of epistemology? To be fair, they each have their strengths, but the most important element to consider is which one best understands the reality and idea of God. After all, as all three men believe, God is necessary for any epistemology (also see Proverbs 1:7), no matter how nuanced, to work. Therefore, if one cannot properly account for God, this poses a difficulty for any attempt to obtain knowledge through their epistemology. Through analysis, it becomes clear that Descartes’ view of epistemology is the one which can most accurately account for God.
(Of course, absent the Bible, none of these men (or any men) will be able to come to a full nuanced understanding of who God is and what his attributes are. General revelation as discussed in this paper can bring us to a god, but not necessarily the God of the Bible.)
Descartes started our controversy with his Meditations. Unsettled that his understanding of the world is based entirely on the accounts of others, Descartes attempts to doubt everything that he has ever thought to know. But he finds there is one proposition indubitable: that he doubts. As R,C. Sproul brilliantly puts it in his book The Consequences of Ideas, "To doubt doubt is to doubt."
From this, Descartes draws two conclusions. First, he exists (cogito ergo sum) as in order for doubt to exist, someone must exist. Second and more importantly, Descartes reasons that the only way he can doubt is if he has an idea of God.
Descartes understands that to doubt is to discern imperfection. Since imperfection can only exist in contrast to perfection, Descartes reasons he must have an image of perfection. From here he reasons that the cause needs to be as strong as the effect. To illustrate, when you get slapped in the face, there must be an equal amount of muscular strength (cause) as the force of the impact (effect).
But as imperfect finite beings (alleged cause), we cannot create an image of a perfect, infinite being (effect). Further, since we have never perceived God either, we must have innately held this notion since birth. Ultimately, that means that God exists and placed in us the idea of perfection, more accurately known as the idea of God.
From this innate knowledge, Descartes builds the rest of his epistemology declaring that the things which we clearly and distinctly perceive can indeed be trusted because a perfect God could not be a liar.
One might question how Descartes’ proof for the existence of God fits within the parameters of Romans 1:20, which states that, “For the invisible things of him from the creation of the world are clearly seen, being understood by the things that were made, even his eternal power and Godhead, so that they are without excuse.” It does not seem like Descartes is explaining that God exists based on what is seen in the “creation of the world.”
However, as reported in the A Greek-English Lexicon of the New Testament and Other Early Christian Literature, the Greek word translated here as “Seen,” – kathoratai (from kathoraō) – is most literally translated “perceive, notice, also of inward seeing.” Thus, it would seem that the scripture is not making a case that our sensory experiences allow us to find the truth about God, but natural revelation more generally.
Further, it is important to note that our minds are part of the “creation of the world,” as well as the “things that were made.” Thus, when Descartes examines his mind, he is basing his idea of God on that which he sees in the creation of the world and understanding from the things that were made.
Then comes Locke. According to Locke, all people were born as a tabula rasa – blank slate – with no innate knowledge. Instead, Locke opines that we learn about the world exclusively through our sense experiences. Locke points out that children and the uneducated do not seem to understand these so-called “innate truths” until someone explains it to them. But if a statement must be learned, it cannot be innate.
While this argument may be compelling for those things which Descartes describes that we “clearly and distinctly perceive,” this argument does little to confront the origin of the idea of the perfect and infinite being that we call God. In order for Locke’s epistemology to form an understandable picture of the world, he would have to show that God exists purely from our sense experiences.
This poses a problem for Locke as no man has actually observed God. So Locke must argue that we get the idea of God by observing all these attributes God is said to have. We do not see perfection in this world, but we do see goodness; we do not see omniscience, but we do see knowledge. For Locke, all we must do to find God through our senses is to take our sensual perceptions of good character traits and imagine them as infinite.
But this cannot account for our idea of God. For one thing, God is not a cumulative being; he is not just a combination of all these various character traits. Rather he is the perfect encompassment of all these traits in one being. We perceive these traits individually and cannot comprehend them together unless we were given that innate knowledge from the start.
Additionally, Locke’s view is that we have placed all of these qualities together to form our idea of God, but how did we know which qualities to put together? Without an innate knowledge and idea of God, then we are left with no way of knowing what is and is not godly. Hence, at the very best, Locke has smuggled in his own view of God, or put another way, he has smuggled in his innate idea of God.
Perhaps most damning of all, Locke argues from the basis of imagining certain observable traits infinite, but we cannot observe infinity through our sensory perceptions. Indeed if we are going to have the idea of infinity, it must have been some form of innate knowledge.
Seeing the pitfalls of Locke (and Descartes to a degree) Kant attempts to bring Descartes’ rationalism and Locke’s empiricism to a synthesis. It is then Kant’s contention that Locke is correct in stating that we have no innate ideas, but Descartes is correct that we have innate structures or categories.
In other words, we have certain axioms, such as the law of causality and the concepts of space and time that allow us to draw conclusions from our sensory experiences. Without either our innate structures (reason) or our sensory experiences, we would have no truth.
It is then that Kant realizes that epistemology without God is meaningless because we would have no reason to trust our senses or our reason without the Lord. Yet Kant understands that we have not perceived God and cannot prove God from our experiences even with innate structures. Thus, Kant argues that we must postulate God’s existence.
Since God does exist, it is not obvious that this would pose difficulty. But as aforementioned, Romans 1 indicates that either through our reason, our senses, or both, we should be able to prove God from general revelation alone (though not necessarily all attributes of the Christian God). Therefore, when Kant argues that his epistemology has to assume God, it does not account for the reality that God has revealed Himself to man through His creation.
Further, to postulate God’s existence, we need to have an idea of what exactly it is that we are assuming exists. Locke’s attempts demonstrate that we cannot reach the idea of God through our sensory experiences. After all, no matter how many innate structures you have, your sensory experience cannot go from time to infinity or from place to omnipresence. As a result, without the innate idea of God, we are unable to postulate that God exists. In other words, the only way we can get at the idea of God – the foundation for all epistemology – is if we accept Descartes’ epistemological distinction of innate knowledge.
Ultimately, both Locke and Kant’s epistemological models fall short for the same reason – they are unable to account for our idea of God. This is the foundation of all epistemology, and so without this foundation, Locke and Kant’s models simply cannot bring us to any knowledge. In contrast, Descartes’ model, because it accepts the idea of God as innate knowledge, provides the foundation for knowledge. Consequently, it is the better model of epistemology.