Epistemology is a word that means the study of knowledge and truth, while etymology is the study of the origins of words and how those words have changed throughout history. When we use etymology to help break down the word “epistemology” we learn that the definition of “truth” comes from the Indo-European word *deru meaning “tree” and that “knowledge” comes from the word *gno meaning “diagnosis.” In retrospect this means that epistemology has many branches and roots that inform knowledge and truth. Three philosophers who help us better understand the concept of epistemology are Plato, Henry David Thoreau, and Jean-Paul Sartre. Although they come from different time periods, these three have a deeper understanding than most that should be re-examined. In Plato's "Apology of Socrates", this implies two things: 1) knowledge is unattainable to humans, but attainable by gods, and 2) knowledge is supernatural. This quote helps support the implication that knowledge is obtainable only from the gods: “…but the truth is, O men of Athens, that God alone is wise; and in this oracle he means to say that the wisdom of men is little or none...” The implication that knowledge is supernatural may be supported by the following quotation: “Can a man believe in spiritual and divine agencies, and not in spirits or demigods? He can't. I'm happy to have gotten that answer, with the assistance of the court; yet you swear in the indictment that I teach and believe in divine or spiritual agencies (new or old, it does not matter); in any case I believe in spiritual agents, as you say and swear in the affidavit; but if I believe in divine beings, I must believe in spirits or demigods; - It is not true? Yes, it is true, by... paper... he did not create himself, yet he is free, and from the moment he is thrown into this world he is responsible for everything he does." In general, Sartre is saying that we are the rulers of our lives, that we must take responsibility and, regardless of what we believe, it cannot be otherwise. Plato, Henry David Thoreau and Jean-Paul Sartre are three philosophers who knew exactly what they stood for and exactly how express it. Although Plato comes from the classical style, Thoreau from the romantic and Sartre from the modern, they all have pieces that remain timeless and are still able to connect to today's technological world. we are able to better understand our history of the study of knowledge and truth. We are able to attempt to gain our knowledge of the subject, of the nature of knowledge.