The meaning of such statements: "what we already know as A, that is what we have found the content of A, also has a content of B ". If the object of knowledge altogether unknown, we have an opinion, the grammatical expression of which is an impersonal sentence, like "thunder," "boring," "light" and etc. This kind of opinion only on the external expression of his impersonal, ie, no object. In fact, it is also directed at an object and something about it expresses, but here the subject is uncertain, unmarked in the concept. Such an impersonal proposition is an existential proposition, "something is A," or "And there is." "Thunders" means "thunder is." The statement "A is B" can be reduced in meaning to existential propositions. As it stands, "along with the content of A is also in the content," then it can be expressed in the impersonal form "is the content A and content B", which is equivalent to an existential statement "the content of A and B content am. " In future, this opinion is written in the form of "A + B is." Thus, any objective, in terms of knowledge can be expressed in the form of an existential proposition. The statement "there is a" refers to an indefinite itself the subject of X, in which structure is A, and this is expressed by an indefinite subject in the word "is". This implies that every subject knowledge involves cognitive gaze direction to the unknown, to some , which sought and was called to the content of A.