Abstract: Aristotle's analysis of touch occupies a core position in his sensory science. Sense is defined by sensibles， and each particular sense corresponds to its exclusive particular sensible. However， due to the diversity of objects of touch， there will be many kinds of touch， which violates the basic principles of the sensory science. The key to solving this problem lies in exploring the essence of the organ of touch， which is the material base of touch. Therefore， we are committed to proving that the flesh has dual roles of organ and medium. It is divided into universal organ and primary organ. From the perspective of primary organ of touch， touch can maintain its unity. Aristotle's exposition of the science of touch is of great significance. It is not only a comprehensive analysis of the relationship between organ and medium， but also a fundamental criterion for judging whether an animal is alive or not.

Key words: Aristotle; touch; flesh; organ; sensory science