Up until Aristotle`s time, there were either the naive materialistic views that considered the world merely as a sensory perceivable reality, as a system based on the same material basis, or there were absolute idealist views that by connecting the real being only with idea and mind, accepted the sensory world as a shadow and illusion and considered the knowledge that were taken from the sensory experiment not as truth and knowledge but as a judgement. Aristotle preferred to unite form and matter. Unlike Plato, he sought ideas not above things but in things themselves and replaced idea-eidos with form which determined the essence of the thing and its function.