Firstly, what does epistemology even mean? We could say that it is an inquiry, within the field of philosophy, that tries to understand concepts we apply to knowing things, such as: beliefs, that are; strongly supported by evidence, justified, or well confirmed." (Sober, 2001; pg149). How do we know when we have knowledge? What suffices for having knowledge? The Classical definition of knowledge, the JTB theory, has attempted to answer this. The JTB theory states that, to have knowledge one must have a justified, true belief. Basically, this says that if you have knowledge that God exists (whether God actually exists or not is not the point right now) you must have a justified, true belief about the existence of God: " if you know that God exists, then you must believe it to be so, if you know that God exists, then it must be true," (Sober, 2001; pg152) and "you must also have some kind of way to justify (reason, prove) your true belief." (Sober, 2001; pg153). There is a flaw. What if it were false that God existed? Your justification, then, would have been incorrect. Both strong and weak justification play an important role in epistemology, by using a process called induction: the use of unbiased information, outside of a belief, to provide good, strong or weak, justification for that belief. This is important because sometimes there is no absolute guarantee that our beliefs can be plainly justified. This is where strong and weak justification enters into play.
Rene Descartes, "who is sometimes described as the father of modern philosophy," (Sober, 2001; pg158) was a French philosopher during the seventeenth century. He attempted to develop a form of epistemology known as Foundationalism, or strong justification. Foundationalism is divided into two categories: " Foundational beliefs (which are perfectly solid) and Superstructural beliefs (which count as knowledge because they rest securely on that solid foundation).