As an important reason this circumstance stands against wide popular beliefs about «uncertainty and an inefficiency» of practice as criterion of objectivity of the knowledge, more increasing declaring about itself and in domestic philosophy. For example I.Kasavin writes «The norm demanding of use of criterion of practice is nonfunctional when it is a question of world-wide-historical public practice and about distinction of materialism and idealism: it is not internally connected with the concept of true when the concrete knowledge and a concrete practice are meant. In the latter case more applicable are private methodological norms and criteria of true...». The author of quoted clause supports such pluralism of criteria of true among which practical function is not allocated a special place.
The methods and the principles, carrying out its basic constructive function in cognitive creativity, are not fenced off, certainly, from correcting, verifying with the norms which have developed owing to practice of knowledge, procedures etc. Methodological principles can reveal effectively enough the conformity with valid denotes to any side of content or the form of true. Let´s remember Cartesian "self-evidence", Leibniz´s "non-contradiction", Kant´s formal criterion and others. Being limited in this profile, we are not capable to measure the rich content of true´s representant. The methods and principles even in dialectic set do not carry out a role of universal, objective criterion.
It is clear, the practice as criterion of true also is not certain "magic stick". Its relativity and limitation follows from concrete historical character of practice, consists in insufficiency of separate practical act and sometimes and the big number of acts for definition of the true or false representations; endless of positions and conclusions of practice takes place. Moreover, it is helpless in cases of temporarily or essentially not relative with the object of reflection of forms of knowledge. The subject of knowledge can be disoriented due to erroneous representations. But it sometimes leads to practically significant result. The food for reflections and doubts in occasion of capacity of criterion of practice is given also with ambiguous dialectics of social ideals and real our achievements what really we can just put the question: Are we aware that the relation of theory to the practice is dialectic?
Nevertheless, only the criterion of practice is absolute and defined and in the sense that it establishes objectivity of true, its results of true estimations appear finally in known frameworks and conditions. It is hardly logical to include in a definition the absoluteness of the criterion of practice and its uniqueness as the criterion of true. It is only consequence of absoluteness of criterion. All other kinds of the cognitive activity accepted quite often as a criteria of true, appear to be methodological principles according to its content, and according to the function and result of the content of objective knowledge is the criteria of error.
Introduction of the last concept in gnosiology is to expedient us. It is thought close to negative criterion of true of Kant as necessary, but not sufficient to the condition of objectivity of knowledge. Formal-logic, methodological principles are capable to testify of errors, sophisms, paralogism but do not guarantee the validity of representants and in this sense if true act as criteria, so they are not true but errors. If criteria of error (they are a lot) cancel inadequacy from knowledge, the criterion of practice besides accumulates in it true.
Opening the criterial functions of practice in the Marxist theory of knowledge, as a rule, reduce to one of them, that is the function of ascertaining of the validity or false of an image. It is thought, very important creative aspect - in fact criterion of practice thus is ignored, being a kernel of a substantiation of knowledge, provides its development, translating one cognitive form into another, transforming true in knowledge. This moment initiates the «last» «segment» where by means of criterion of practice the original knowledge of true, its substantiation and the simultaneous comprehension by the subject necessary for relative end of all dialectic way of «knowledge of true» is directly carried out. The last word-combination is not a tribute of Hegel manner of expression; German philosopher considers it as substantial, independent and necessary component of spiritual manufacture.
Thus, it is possible to speak about bi-functionality of criterion of practice in which there are two parties: criterial and constructive (creative). Often they are shown in indiscernible unity; more precisely are not shown but contained in essence. But when representation is false, function of criterion of true degenerates, degenerates in verification, ascertaining of its gnosiological definiteness. If the representation put on trial is true the practical criterion carries out subjective comprehension of its validity, reception of knowledge. The accumulation of knowledge is based on this creative function of practice.
One of the moments of Popper´s falsificationizm is the denying constructive profile of function of criterion of practice. Reducing the content of science to the trues denied during their verification, Popper simplifies a gnosiological role of practice and experiment, seeing in them only verifying function. In essence Popper denies the true in itself, especially - achievement of knowledge by its transformation by criterion of true. All this deprives science of cognitive content and to a certain extent consequence of an identification of absolute and objective true and non-recognition of dialectically capacious nature of criterion of practice. Really, from the presence of the objective content in true follows its absoluteness (actually, it is the same ideal content, objective concerning to the subject and absolute concerning to object), but the true includes cognitively uncertain and in this sense is characterized as well by relativity. Popper ignores similar interpretation of concept.
For the sake of justice we have to notice: Popper´s concept appears as the panoramic picture of scientific knowledge manufactured by large stroke of paint-brush; he does not take interest in nuances. Concretizing its details further, it is possible to notice that to known methodological and world outlook preconditions of the given conclusions, one more is added. Even considering that circumstance that Popper carries out not gnosiological but epistemological approach to knowledge, and of a science the true has essential orientation, is focused on knowledge and expression of essence, its requirements to the given concept are represented strong enough, identifying the objective contest of true with true itself. The rigid criticism of relativism and subjectivity of neo-positivists carries away Popper in other extremity (and that intention as was necessary to expect, eventually, has pull together it with a position of criticized).
To add, Popper carries out the maximal approach to the question of verification of the validity of knowledge. Without consideration limitations and uncertainty of practice as criterion of true, the founder of critical rationalism stays apart not only from necessary, though also subjective (as it considers) criteria of coherence, pragmatism (instrumentalism), conventionalism, etc., but declares insufficient for true knowledge both empirical and practical criteria . That is why falsificationism as the method with all its efficiency and value in a science, does not specify true, but (i.e. it appears criterion of error) only testifies to unsuitability of the theory and necessity of its change.
The tradition in which practice is exposed to the analysis as a way of substantiation of knowledge, in the western methodology of a science is supported not only by pragmatism. For empirical knowledge it contains, in particular so-called fundamentalist and not fundamentalist theories of the justification. The first validity as criterion of cognitive forms select certain indisputable bases (on manners of criterion of evidence of Descartes). In some not fundamentalist theories results of a science correlate to practice. However, its essence and gnosiological functions are underestimated: criterial function is narrowed to revealing pragmatical utility at knowledge.
Stated above bi-functional criterion of practice is fruitful in judgment of a parity of true and knowledge and denies the known points of view: « knowledge and true are synonyms», or «knowledge» and «true» are not identical categories. Any true knowledge, but not any knowledge is true», or «knowledge is such result of cognitive activity which can be estimated as true or false». The conclusion is more logical: any knowledge is true, but not any true is knowledge.
The article is admitted to the International Scientific Conference " Problems of national educational standards´ international integration "; France, Great Britain, 2007, April 20-27; came to the editorial office on 01.02.07
 Kasavin I.T. Descriptive understanding of true // Philosophical science, 1999, №8, c.66
 See: Popper K. The true, rationality and the growth of scientific knowledge// Popper K. Logic and the growth of scientific knowledge. M., 1983.
 Popper is not alone here. Let´s remember Heidegger: «The question of essence of true comes from the question of true of essence». Heidegger M. About essence of true.// Philosophical science, №4, 1989., - 103 p.
 Popper K. The true, rationality and the growth of scientific knowledge// Popper K. Logic and the growth of scientific knowledge. M., 1983., - 339-340 p.