Theories of knowledge

Theories of knowledge
What is knowledge?
How is knowledge acquired?
What do people know?
How do we know what we know?

Epistemology is concerned with the nature and scope of knowledge, and whether knowledge is possible. Among its central concerns has been the challenge posed by skepticism and the relationships between truth, belief, and justification.

Specific theories of knowledge acquisition
Empiricism is one of several competing views about how we know "things", part of the branch of philosophy called epistemology, or "the Theory of Knowledge". Empiricism emphasizes the role of experience and evidence, especially sensory perception, in the formation of ideas, while discounting the notion of innate ideas. In the philosophy of science, empiricism emphasizes those aspects of scientific knowledge that are closely related to evidence, especially as discovered in experiments. It is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world, rather than resting solely on a priori reasoning, intuition, or revelation. Hence, science is considered to be methodologically empirical in nature. These philosophers believe that for any knowledge to be properly inferred or deduced, it is to be gained ultimately from one's sense-based experience.


Specific theories of knowledge acquisition
Empiricism - is generally a theory of knowledge emphasizing the role of experience, especially experience based on perceptual observations by the five senses. Empiricism emphasizes the role of experience and evidence, especially sensory perception, in the formation of ideas, while discounting the notion of innate ideas (except in so far as these might be inferred from empirical reasoning, as in the case of genetic predisposition).

Rationalism - is "any view appealing to reason as a source of knowledge or justification" (Lacey 286).
Knowledge is primarily (at least in some areas) acquired by a priori processes(knowledge that is known independently of experience). A theory in which the criterion of the truth is not sensory but intellectual and deductive" They believe that before humans can understand the world, they first need to understand themselves; the only way to accomplish that is with rational thought.
Man is composed of two parts, a body and a soul. The soul itself has two principal parts, an Irrational part, which is the emotions and desires, and a Rational part, which is our true self. In our everyday experience, the irrational soul is drawn down into the physical body by its desires and merged with it, so that our perception of the world is limited to that delivered by the physical senses. The rational soul is beyond our conscious knowledge, but sometimes communicates via images, dreams, and other means.
Rationalism is a method or a theory in which the creation of truth is not sensory by intellectual and deductive. There is a knowledge that is innate or born inside of us, that is to say that there are forms of knowledge that exists within our minds from the time we are born.

Constructivism
Constructivists maintain that scientific knowledge is constructed by scientists and not discovered from the world. Categories of knowledge and reality are actively created by social relationships and interactions. These interactions also alter the way in which scientific episteme is organized.
They argue that one must already have Reality in mind—that is, one must already know what Reality consists of—in order to confirm when one has at last "hit bottom.

Analytic-synthetic distinction-is a conceptual distinction, used primarily in philosophy to distinguish propositions into two types: analytic propositions and synthetic propositions.
Analytic propositions are those which are true simply by virtue of their meaning while synthetic propositions are not; however, philosophers have used the terms in very different ways.
Other philosopher believed that:
analytic proposition: a proposition whose predicate concept is contained in its subject concept
"All bachelors are unmarried."
"All triangles have three sides."

synthetic proposition: a proposition whose predicate concept is not contained in its subject concept.
"All bachelors are unhappy."
"All creatures with hearts have kidneys."
Some propositions are such that we appear to be justified in believing them just so far as we understand their meaning. For example, consider, "My father's brother is my uncle." We seem to be justified in believing it to be true by virtue of our knowledge of what its terms mean. Philosophers call such propositions "analytic." Synthetic propositions, on the other hand, have distinct subjects and predicates. An example of a synthetic proposition would be, "My father's brother has black hair." Kant held that all mathematical propositions are synthetic.


Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Epistemology#Acquiring_knowledge

Skepticism – the belief that some or all human knowledge is impossible. Skeptics argue it is better to suspend belief than to rely on the products of reason that is doubtable. Denies the possibility of a complete or genuine knowledge of an objective world.
Skepticism is related to the question of whether certain knowledge is possible. Skeptics argue that the belief in something does not necessarily justify an assertion of knowledge of it.

Traanscendental idealism - a doctrine founded by German philosopher Immanuel Kant in the eighteenth century. Kant's doctrine maintains that human experience of things are similar to the way they appear to us — implying a fundamentally subject-based component, rather than being an activity that directly (and therefore without any obvious causal link) comprehends the things as they are in and of themselves.