David Hume’s Fork is one of the many answers to Descartes’ Challenge. The Challenge asks, “How do I know the outside world matches my sense data?”. Hume’s Fork responds by stating that there are only two types of “justified knowledge”, the knowledge being the certainty of what you know to be true, which is asked for in Descartes’ Challenge. The first type of knowledge is a synthetic, a posteriori claim, which we make based on the sensations we experience as raw, forced data. One example would be an apple sitting on a table. We can pick the apple up, eat it, and there are no doubts that it is an apple on a table and nothing else. The second type of knowledge on the fork is an analytic, a priori claim, which we can make provided we have already
