Epistemology is intertwined with the common discipline of philosophy. Both are essentially the process of understanding "truth," and determining the nature of "knowledge." Though this subject has been interpreted since the era of classical Greece, epistemology continues to have a major global impact on political and social activity in the 21st century.
Derived from the concept of the Greek term epistome, meaning "knowledge," it is coupled with the term ology, meaning "science." There are three primary questions of epistemology: What is knowledge? How did we acquire the knowledge? How do we know what we know? The aggregate result is awareness of the essence of what is commonly considered the understanding of truth, or "philosophy." There are essentially two schools of thought in the discipline, with the many various theories extending from the two. It is essentially the study of human existence.
The two primary schools of thought were developed in the 4th century B.C. Modern epistemology began its advancement in this period with the writings of Plato. The periodical beginning was prior to Platonist writings, by virtue of his experience with his mentor, Socrates. Socrates wrote nothing and technically was not a philosopher. He was a sage moralist, very similar to the concept of Jesus, and most information on Socrates came from Plato.
Sometimes it is difficult to tell the difference between the two, given that Plato wrote the primary accounts of Socrates' teachings. The era of Plato was one of a volatile political environment. From Socrates comes the concept of the soul, or psyche, allowing for individual moral thought without need of direction from the perceptive governmental super-parent, though he would identify that as his reasoning for accepting his fate at his trial for impiety.
Plato's early theory development occurred while the local authorities were busy prosecuting Socrates. He was fortunate enough politically to establish his school later and begin teaching his concept of "becoming," based on the theory of the individual spirit that Socrates had claimed. The essence of his theory of forms couples with his theory of Ascension to the One and became the template for most contemporary religion.
Plato suggested that individuals have a priori, or innate, knowledge. People are essentially imperfect spiritual habitual entities in a physical and changing world and we are attempting to be perfect, but our imperfect constantly-changing condition prohibits that status in this lifetime. What we are attempting to be in this imperfect life is what we will be in the next dimension of eternity, which eliminates the condition of change. In Plato's political writings this theory gets collectivized, as his preferred form of social structure and government was sympathetic to the ruling class, suggesting that society was best served with leadership, or rule, under a philosopher/king.
Plato's primary student was Aristotle. After being trained in this particular understanding of knowledge, Aristotle rejected the premise. He claimed that knowledge was a posteriori, or external. Termed the concept of "being," Aristotle said that knowledge required empirical evidence. Laying out the foundation for materialism, Aristotle claimed that evidence of knowing stems from experience and observation, not merely from internal thought. He did not completely reject Plato's concept of internal existence, but suggested everyone is born with a "blank slate" and we are all essentially products of our experiences and environment.
His concept of moral virtue was also different from Plato. Instead of a collective or appointed morality, which Plato may have suggested as an appeasement to the ruling class, Aristotle claimed that moral virtue was a hexus, or a state of mind, involving the individual, concerning choice, and lying in a mean, whereby the individual acts rationally according to reason and properly feels the emotions and desires associated with the action.
Politics being essentially how we exercise our attitudes toward other individuals, regardless of station in life, his definition of moral virtue has been the anchor of his political teachings. He rejected the necessity of a monarchy in a society where the reasoning ability of the common individual was collectively sufficient to provide an orderly social structure with a minimal power structure.
From these two distinct schools of thought all later philosophers would arise. They establish some premises for political and spiritual theoretic splits as well. With every understanding of knowledge being either internal or external by laws of physics, metaphysics becomes the foundation, for not only how we understand knowledge, but how we should morally move forward as a society and apply the knowledge effectively.