# Introduction to Philosophy/What is Epistemology

The word 'epistemology' comes to us from ancient Greek: the noun episteme meaning 'knowledge' and the suffix -ology meaning 'the science of' or 'the study of.' So, literally speaking, epistemology is the study or investigation of knowledge itself. It is also often referred to as Theory of Knowledge. Epistemic knowledge is not about what we know, but about what it means to know.
Epistemology seeks to answer basic questions about how human beings perceive the world and gain knowledge about it. The more prominent of these include:
* Is there an external world? How can we be certain?
* How does memory work? How can we know that our memories are genuine?
* What is the nature of perception? To what extent does current knowledge affect future perception?
* What knowledge is inherent to humans and what is learned after birth? Can new facts be assimilated without innate concepts?
* To what extent are inferences based on perceptions valid? What is the proper way to make such inferences?
It is helpful to note the basic (Socratic) distinction made between beliefs, which hold to opinions, and knowledge, which holds to 'truth'. Knowledge concerns apodictic facts that are absolute and simply cannot be false (while opinions can be and often are false). According to Karl Popper, the only way we can distinguish between truth and not-truth is by subjecting test-statements to experimental invalidation. Plato thought otherwise; he believed that truth is not subject to invalidation.
So then the epistemological question: Where does our knowledge come from? And to take it further (as many philosophers have): What are the limits of human knowledge? Here one should read up on the two main competing philosophical branches of the early modern age: Rationalism and Empiricism. Rationalist thinkers like Descartes argue that all knowledge comes from reason, and everything in the world of homo cogitans is fundamentally rational. It is through the human mind that the human knows. Empiricists (at that point, the British thinkers: Berkeley, Hume, Locke) insist that most, if not all, *real* human knowledge can only be arrived at through human experience. It is through the human senses that the human knows.
There is also the theologically-driven idea of knowledge as (divine) revelation (think God, by his Spirit, giving to the writers the Holy Bible). There is an interesting blurring of the lines separating belief and knowledge here. St. Augustine gives us an eloquent discussion of reason vs. faith.
One issue that is of interest to many epistemologists is the analysis of knowledge, that is trying to find an answer to the question "what conditions need to be satisfied to say that someone knows something?" For a long time, the conditions seemed clear to most philosophers: to know something, you must believe it, it has to be true and you have to have a justification for believing it. The problems raised by the Gettier problem have reopened this question for many and a great number of new problems have arisen. This kind of question is considered the most general of questions in epistemology, while concerns about, say, the different ways of knowing are a much more specific set of questions within epistemology.

## Reference and further readings

* Epistemology at Wikipedia.