Critical thinking is self-guided, self-disciplined thinking which attempts to reason at the highest level of quality in a fair-minded way.  People who think critically strive to always improve their reasoning abilities and to be aware of the common pitfalls of human reasoning – irrationality, prejudices, biases, distortions, uncritically accepted social rules and taboos, self-interest, and vested interest.  They strive to improve the world in whatever ways they can and contribute to a more rational, civilized society. They avoid thinking simplistically about complicated issues and strive to appropriately consider the rights and needs of relevant others. They embody the Socratic principle:  The unexamined life is not worth living, because they realize that many unexamined lives together result in an uncritical, unjust, dangerous world.