The mirror neuron was discovered from the brain of pig-tailed monkey, Macaca nemestrina in 1992 by accident (16). Mirror neurons will discharge not only when an individual executes some action but also when it looks at others (other individual or experimenter) execute the same action. It is named because it connects other’s action with one’s own action like a mirror. It is elucidated that mirror neurons will carry out an important function when an individual understands and imitates others’ action (17-19). Mirror neurons are also found in both hemispheres of human beings, corresponding to Bloca’s area at the frontal lobe in the case of the left hemisphere. Since it has been known before the discovery of mirror neurons that human neonates of several weeks after birth already imitate the facial expression of others, a neural system which reconciles seeing with doing actively has been foreseen to exist (20). Mirror neurons showed the distinct neural basis of the fact. What kind of fact is it that ‘I’ can recognize ‘my’ own mirror image as ‘my’ own image? In order to recognize ‘my’ own mirror image as ‘my’ own image, ‘I’ should comprehend accurately that mirror images move in the same way as when ‘I’ move ‘my’ own hand or face while looking at the mirror. On that occasion, when ‘I’ am looking at the action done by ‘my’ own mirror image, since ‘I’ am doing the same action as that done by ‘my’ own mirror image, in order to comprehend that mirror image is same as ‘my’ own image by objectifying it, the function of mirror neurons which discharge not only when ‘I’ look at the action shown by mirror image but also when ‘I’ do the same action is necessary. Due to the function, ‘I’ can comprehend that the action done by mirror image is same as ‘my’ own action. However, that alone is not sufficient to recognize that a mirror image is the image of ‘myself’. The reason why is that even if ‘I’ can comprehend in such a way ‘I’ cannot find the meaning from that fact unless ‘I’ have strong interest in ‘myself’ looking at mirror image. Accordingly, a sufficient condition to recognize a mirror image as one’s own image is probably the ability to distinguish tiny or large differences between one’s own self and other people along with strong interest and persistence in one’s own self. Those are supposed to be formed through the relationship in which an infant distinguishes its mother and being distinguished by the mother due to intimate contacts continuing from soon after birth with mother. Actually, when expressed as follows, it is understandable that this mirror neuron’s function (B) and consciousness (its introspective characteristic) (A) is very similar when giving attention to ‘I’ and ‘others’. A: When ‘I’ have some thinking or feeling, or when ‘I’ do some behavior, ‘I’ can see it as if ‘others’ have or ‘others’ do. B: It discharges not only when ‘I’ do some behavior but also when ‘I’ see ‘others’ do the same behavior. ［B］can be , with the mediation of mirror neuron’s discharge, substituted by next equality: 〈 ‘I’ do some behavior= ‘I’ see others do the same behavior 〉 On the other hand, ［A］is the same as: 〈 When ‘I’ have some thinking or ‘I’ do some behavior, ‘I’ see those as if ‘I’ see those reflected in a mirror 〉 When these two are combined, and if it can be realized in the neurophysiological process within a brain that〈 ‘I’ will make what ‘I’ have some thinking or ‘I’ do some behavior as if it were reflected in a mirror 〉, then it is presumed that ‘I’ can see the process as others’ thinking or behavior by the function of mirror neurons. Based on this presumption, presented is the hypothesis at the beginning (7). As for this hypothesis, it can be considered to be indispensable that both the right and left hemispheres can hold an equal position about decision-making, namely the right hemisphere changes into another personality to be able to make decision freely together with the left hemisphere. By this fact, both right and left hemispheres face one another such as they face a mirror through corpus callosum connecting both hemispheres homotopically by more than two hundred millions of nerve fibers (21), then the mirror neurons, originally monitoring the action of others by visual information, grasp the transition or communication of nerve signals between right and left hemisphere as the information as if it were from others, as a result self-objectification is accomplished.