It may be said that normative sciences, such as education, law, management and administration, rely upon at least two kinds of theoretical possibility: Possibility of social sciences (as descriptive) and possibility of objective value judgment. Both questions have been controversial in the circles of philoso-phers of social science and of moral philoso-phers respectively. In this essay, attempts are made at clari-fying the problems and justifying finally possibility of both theories. Based on the arguments developed here, an attempt is also made at utilizing lcgical studies, what is called “decntic logic”, that have been under-taken among contemporary lcgicians. This study is not complete but preliminary, of course. However, it avails us to formalize, at least partially in a limited context, ideas as to educational values together with related facts. It is argued, first, that social science is legitimately possible to be a scientific study, since we have ideas of prediction in a certain way. Of course, predictability of human¬social phenomena is not so accurate as that of natural phenomena. Accordingly, we cannot identify sccial sciences with natural sciences. But predictability of human-social events can be often seen in ordinary affairs of human-social life that can be described in terms of culture. The culture of a society evidences the idea of predictability, without which human beings cannot live in and with the culture. Secondly, it is argued that value is possibly an object of knowledge, i.e., that value statement can be a kind of genuine descrip-tive statement. Many of moral or axiologi-cal theorists have committed themselves to linguistic confusions. Some mistakenly be-lieve that the meaning of words involves their emotional or attitudinal functins, and thus that value terms cannot be a cognitive object. Others, committed to the referential theory of meaning, mistakenly confine the meaning to natural substances or properties. It is argued in this essay that value terms refer to properties or characteristics “instituted” by the agent, and that value terms should be understood in accordance with the context in which they are used, either moral, aesthetic, private taste or other. Finally, it is discussed that logical" studies are applicable to systematization of the normative science. Among others there have been developed studies of G.B. Von Wright, A.R. Anderson and O.K. Moore.