Skepticism

Skepticism is a philosophy and school of thought first represented in the Classical Kalopia by Polyeides of Eleopolis. Skepticism is a philosophy which questions or doubts any kind of knowledge or belief. Skepticism isn't only seen in philosophy, but also in politics, religion and science. One of the most common ways of Skepticism is Agnosticism, which doubts/questions the believes coming from religions, such as God.

Radical Skepticism, which states that nothing can be certainly known or that rational belief/knowledge cannot be possible and rejects it, is often related with Nihilism, and more specifically, Epistemological Nihilism, which states that nothing can be truly known and knowledge cannot be achieved.

Classical Skepticism
From the Classical Kalopia, Butacidas stated "nothing exists, if something existed we couldn't know it, and if we could know it we couldn't communicate it." Sokriatos also had some skeptic tendencies. But the most important representant from Skepticism, at least from the Classical times, is Polyeides of Eleopolis.

Modern Skepticism
In Modern times, Skepticism is still very popular amongst population, especially in the form of Religious Skepticism or Agnosticism.