Epistemology is narrowly defined in the Stanford Encyclopedia of Philosophy as the study of knowledge and justified belief. It is a branch of philosophy that actually studies the nature, objectives, origins and methods of scientific knowledge. The questions it asks are: What are the necessary and sufficient conditions of knowledge? What is the source and structure of knowledge and what are its limits? The name of this field comes from episteme, which means knowledge, and logos, which means study or theory. According to epistemology, knowledge is true belief, but don’t think at the term “belief” as how we use it in our natural language. One must also not consider a belief born from logical fallacies as knowledge. So, epistemology studies how belief becomes knowledge, considering that knowledge equals truth (epistemology considers that false propositions cannot be known).
Types of knowledge
The word knowledge can be used in various ways, but the distinction that should be made clear here is the fact that philosophers use this word in a factive sense. However, even the factive usages of knowledge are many and need to be distinguished. Some philosophers believe that there is a clear distinction between “knowing that”, “knowing how”(knowing how to drive a car), and the acquaintance knowledge(this could also be called familiarity); but epistemology is mostly interested in the first type.
As we can see, epistemology focuses on knowledge. However, its main focus is the knowledge of propositions such as S knows that P, where S is the subject who has knowledge and p is the proposition that is known. Epistemology then asks: What are the necessary and sufficient conditions for S to know that P? As I mentioned earlier, there are certain conditions: knowledge requires truth and it also requires belief. But S believing p, for example, could just be a manner of luck, so knowledge also needs justification. This analysis has been shown to be incomplete and it requires another element called reliability. This is called the Gettier Problem, but I will not go any further with that for the moment.
If we sink deeper into this problem we can also distinguish different types of prepositional knowledge. Based on the source of the knowledge, people can have a priori knowledge which is non empirical, meaning that it is independent of any experience and can be obtained with the use of reason. Another type of knowledge is empirical or a posteriori knowledge which can only be obtained by certain senses, experience and the use of reason. Epistemology addresses all kinds of knowledge with different standards and methods for a priori and a posteriori. There are different conceptions here: rationalists believe that all knowledge is grounded on reason, while empiricists believe that all knowledge is based on experience. Another distinction is made when we address collective or individual knowledge. The field of social epistemology studies how collectives of individuals acquire knowledge. Social epistemology studies knowledge in a social context, how human knowledge becomes a collective achievement. For some, social epistemology should retain the same mission as classical epistemology, but others believe that it should be a successor discipline that must replace traditional epistemology.
Sources of Knowledge
In general epistemology knowledge is gained through direct analysis, formalized logical analysis, critical and historical analysis, and experiments. The study of scientific knowledge is made through inductive means and it leads to generalization regarding the process of scientific knowledge and a critical analysis.
The sources of knowledge are perception, introspection, memory, reason, and testimony.
Perception includes the five senses. There should be a distinction made if we actually perceive X or it seems to us that X. In the latter, also called an experience of perceptual seeming, X is false because experience is fallible.
Introspection allows us to know our own mental state. So it is less prone to error since it can be really difficult for me to seem that I might have a certain inner state. So, there is no difference between appearance and reality when it comes to introspection, giving it a special status and making it infallible (even a source of certainty, according to some).
Memory is fallible because it cannot be precise. Something could seem to be a part of our memory, so we could be wrong. Epistemology’s problem with memory is deciding whether it is a source of knowledge about the past. The sad truth is that all we know resides in memory and its reliability is problematic.
This is actually an a priory type of knowledge. Epistemology has some questions prepared for it too: does it exist? Some skeptics deny apriority and believe that everything is empirical. If it is possible, then how does it manifest itself and to what extent? For example, some empiricists argued that a priori knowledge is somehow inferior since it is limited to the realm of the analytic and not about the world. There is also the issue of necessary or contingent truths, but more on that, hopefully, when we will have time to analyze things thoroughly (I promised this is going to be extremely short).
Testimony doesn’t have its own cognitive faculty and the knowledge aquired through testimony is actually coming to know that p on the basis of someone’s saying that p. Epistemology asks why is testimony a soruce of knowledge? Well, it only is when it comes from a reliable source. But how do we decide what is reliable or not when we cannot gain knowledge on that? If we don’t know the grade or reliability of a person that person doesn’t put us in a position of knowing something. (Read this about testimony if you are interested in knowing more, I promise it’s interesting )
I will stop now and just say that there are fascinating subjects in epistemology like: evolutionary epistemology (I think you will see more on this since it’s a current obsession of mine), religious epistemology, moral epistemology, meta-epistemology, etc. I will try to write more on this subject, hopefully on more particular areas.
Sources and further reading: