Exctract from "Lecture on Symbolism", an introduction to Gurdjieff's ideas on the subject.
The words and notions of conversational language become dead and empty, conveying nothing to him who does not carry such knowledge within himself. In the same way as the sensation of tooth-ache cannot be imparted to one who has not experienced it, and just as the difference of colours cannot be conveyed to one blind from birth, and the wealth of auditory sensation cannot be communicated to the deaf, similarly you cannot tell or relate in words the depth of knowledge which has become part of a man's being. The words and notions of different epochs change according to conditions of place and time - humanity has understood this, and by utilizing the language of symbols and formulae more perfect than our contemporary language, has gone on handing its knowledge down to the succeeding generations.
And everybody approaching the symbol and possessing a
complete understanding of it, possesses a perfect synthesis of it, speaking
figuratively he has this symbol within himself. A symbol, by expressing the
knowledge of the laws of unity, has at the same time expressed the path to
Side by side with the basic symbols, as if they absorbed into themselves wider spheres, there started up and sprang into existence in subjection to them other symbols and formulae. Everything in the world is one and is governed by uniform laws, and for that reason the "Emerald Tables" of Hermes Trimegistus put it: "As above, so below." All the laws of the cosmos we shall find in the atom, and in any phenomenon existing as something complete according to laws. The knowledge of the laws of the plurality of the one was always based on the similitude of the microcosm to the macrocosm of man to the universe and vice versa.
The fundamental laws of the 3 and of the 7, of the active, passive and neutral principles, the laws of activity, are to be found and confirmed in everything, and therefore in arriving at a knowledge of the world's structure, man was unable to avoid the path of self-knowledge, as his nearest and always readily accessible object of knowledge was always himself, he being the expression of the action of all the laws of the Cosmos.
The formula "Know thyself" is in this respect full of the profoundest meaning -it is one of the symbols of the knowledge of truth. By becoming acquainted with the symbol expressing the laws of creation, man will learn the laws themselves, and by learning these in himself he threads the path of self-knowledge, and in this sense every symbol teaches us about ourselves. By learning to distinguish the laws of evolution and involution, synthesis and analysis, yes and no, good and evil, energy and matter, forward and retrogade movement, man will also discern the reciprocal action of these laws.