Critical thinking is the analysis of available facts, evidence, observations, and arguments in order to form a judgement by the application of rational, skeptical, and unbiased analyses and evaluation. The application of critical thinking includes self-directed, self-disciplined, self-monitored, and self-corrective habits of the mind, thus a critical thinker is a person who practices the skills of critical thinking or has been trained and educated in its disciplines. Philosopher Richard W. Paul said that the mind of a critical thinker engages the person's intellectual abilities and personality traits. Critical thinking presupposes assent to rigorous standards of excellence and mindful command of their use in effective communication and problem solving, and a commitment to overcome egocentrism and sociocentrism.
In the West, critical reasoning originated from the teachings of the Greek philosopher Socrates (470–399 BC).
Skepticism, also spelled scepticism in British English, is a questioning attitude or doubt toward knowledge claims that are seen as mere belief or dogma. For example, if a person is skeptical about claims made by their government about an ongoing war then the person doubts that these claims are accurate. In such cases, skeptics normally recommend not disbelief but suspension of belief, i.e. maintaining a neutral attitude that neither affirms nor denies the claim. This attitude is often motivated by the impression that the available evidence is insufficient to support the claim. Formally, skepticism is a topic of interest in philosophy, particularly epistemology.
Pyrrho of Elis was the founder of the school of skepticism known as Pyrrhonism.