Philosophical skepticism is a family of philosophical views that question the possibility of knowledge. It differs from other forms of skepticism in that it even rejects very plausible knowledge claims that belong to basic common sense. Philosophical skeptics are often classified into two general categories: Those who deny all possibility of knowledge, and those who advocate for the suspension of judgment due to the inadequacy of evidence. This distinction is modeled after the differences between the Academic skeptics and the Pyrrhonian skeptics in ancient Greek philosophy. In the latter sense, skepticism is understood as a way of life that helps the practitioner achieve inner peace. Some types of philosophical skepticism reject all forms of knowledge while others limit this rejection to certain fields, for example, knowledge about moral doctrines or about the external world. Some theorists criticize philosophical skepticism based on the claim that it is a self-refuting idea since its proponents seem to claim to know that there is no knowledge. Other objections focus on its implausibility and distance from regular life.
Skeptics in Raphael's School of Athens painting. 1. Pythodorus 2. Arcesilaus of Pitane 3. Carneades of Cyrene 4. Pyrrho of Elis 5. Timon of Phlius 6. Theodorus the Atheist of Cyrene
Pyrrho of Elis, marble head, Roman copy, Archeological Museum of Corfu
Sextus Empiricus
Augustine of Hippo
Philosophy is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, value, mind, and language. It is a rational and critical inquiry that reflects on its own methods and assumptions.
The statue The Thinker by Auguste Rodin is a symbol of philosophical thought.
Physics was originally part of philosophy, like Isaac Newton's observation of how gravity affects falling apples.
Aristotle was a major figure in ancient philosophy and developed a comprehensive system of thought including metaphysics, logic, ethics, politics, and natural science.
Portrait of Avicenna on a silver vase. He was one of the most influential philosophers of the Islamic Golden Age.