観念

Also known as ideas

right|thumb|250px|Plato, one of the first philosophers to discuss ideas in detail. Aristotle claims that many of Plato's views were Pythagorean in origin. In philosophy and in common usage, an idea (from the Greek word: ἰδέα (idea), meaning 'a form, or a pattern') is the result of thought. Also in philosophy, ideas can also be mental representational images of some object. Many philosophers have considered ideas to be a fundamental ontological category of being. The capacity to create and understand the meaning of ideas is considered to be an essential and defining feature of human beings.