Gurdjieff from Ouspensky's In Search of the Miraculous (pages 310-311) said:
The humanity to which we belong, namely, the whole of historic and prehistoric humanity known to science and civilization, in reality constitutes only the outer circle of humanity, within which there are several other circles
So that we can imagine the whole of humanity, known as well as unknown to us, as consisting so to speak of several concentric circles.
The inner circle is called the ‘esoteric’; this circle consists of people who have attained the highest development possible for man, each one of whom possesses individuality in the fullest degree, that is to say, an indivisible ‘I,’ all forms of consciousness possible for man, full control over these states of consciousness, the whole of knowledge possible for man, and a free and independent will. They cannot perform actions opposed to their understanding or have an understanding which is not expressed by actions. At the same time there can be no discords among them, no differences of understanding. Therefore their activity is entirely coordinated and leads to one common aim without any kind of compulsion because it is based upon a common and identical understanding.
The next circle is called the ‘mesoteric’, that is to say, the middle. People who belong to this circle possess all the qualities possessed by the members of the esoteric circle with the sole difference that their knowledge is of a more theoretical character. This refers, of course, to knowledge of a cosmic character. They know and understand many things which have not yet found expression in their actions. They know more than they do. But their understanding is precisely as exact as, and therefore precisely identical with, the understanding of the people of the esoteric circle. Between them there can be no discord, there can be no misunderstanding. One understands in the way they all understand, and all understand in the way one understands. But as was said before, this understanding compared with the understanding of the esoteric circle is somewhat more theoretical.
The third circle is called the ‘exoteric', that is, the outer, because it is the outer circle of the inner part of humanity. The people who belong to this circle possess much of that which belongs to people of the esoteric and mesoteric circles but their cosmic knowledge is of a more philosophical character, that is to say, it is more abstract than the knowledge of the mesoteric circle. A member of the mesoteric circle calculates, a member of the exoteric circle contemplates. Their understanding may not be expressed in actions. But there cannot be differences in understanding between them. What one understands all the others understand.
In literature which acknowledges the existence of esotericism, humanity is usually divided into two circles only and the ‘exoteric circle’ as opposed to the ‘esoteric,’ is called ordinary life. In reality, as we see, the ‘exoteric circle’ is something very far from us and very high. For ordinary man this is already ‘esotericism.’
The outer circle’ is the circle of mechanical humanity to which we belong and which alone we know. The first sign of this circle is that among people who belong to it there is not and there cannot be a common understanding. Everybody understands in his own way and all differently. This circle is sometimes called the circle of the ‘confusion of tongues,’ that is, the circle in which each one speaks in his own particular language, where no one understands another and takes no trouble to be understood. In this circle mutual understanding between people is impossible excepting in rare exceptional moments or in matters having no great significance, and which are confined to the limits of the given being. If people belonging to this circle become conscious of this general lack of understanding and acquire a desire to understand and to be understood, then it means they have an unconscious tendency towards the inner circle because mutual understanding begins only in the exoteric circle and is possible only there. But the consciousness of the lack of understanding usually comes to people in an altogether different form.