Epistemology: Sources of Knowledge in Western Philosophy

The Philosophical Origins of Knowledge (Epistemology)

The fundamental problem of knowledge attempts to resolve the question: What is the source of our knowledge? Answers to this question have been proposed by different philosophical schools of thought:

1. Rationalism

   Key Proponents: Plato and René Descartes.

   Rationalists assert that true knowledge is innate, based on reason, and certain. Sensory experience provides only beliefs or opinions, never genuine knowledge. Proponents defend the conception of truth as coherence (internal consistency) and often use logical structures (like mathematics) as a model of connection.

   • They affirm the existence of innate ideas (ideas that do not come from experience).
   • These thinkers are often considered dogmatic. Modern rationalists include figures like Karl Popper (in certain contexts).

2. Empiricism

   Key Proponents: Epicurus, Zeno, the Sophists, and John Locke.

   Empiricists argue that all knowledge comes from the senses and experience (both internal and external), which is fundamentally sensorial. Knowledge is derived through experience, observation, and experimentation. They affirm the concept of truth as correspondence with the facts. The physical sciences serve as the model for knowledge.

   • They deny the existence of innate ideas, viewing the mind as a "tabula rasa" (white sheet).
   • Ancient Sophists argued that sensory experience is the only source of knowledge, but since the senses only inform us of appearances, firm knowledge of reality is impossible (leading to skepticism).
   • John Locke, a key modern representative, distinguishes two types of ideas:
     • Simple Ideas: Derived from inner experience (e.g., thinking, desiring) and external sensation (e.g., feeling).
     • Complex Ideas: Formed by the understanding combining simple ideas (e.g., the idea of a red rose).

3. Synthesis of Knowledge: Empirico-Rationalism

   Key Proponents: Aristotle and Immanuel Kant.

   This school holds that knowledge is obtained from both sensory experience and reason. This philosophy proposes a synthesis between Rationalism (which had become dogmatic) and Empiricism (which had become skeptical).

   In contemporary philosophy, the problem of the origins of knowledge often focuses on scientific methodology: the scientist uses reason to form hypotheses and design experiments, and then uses the senses to carry out and verify them.

Classification of Knowledge and Certainty

A potential classification system for knowledge types or certainty levels:

Connection to / Correct / Belief / Rational Certainty

CPV / CV / CP / C