This article tries to elucidate Kosuth’s intention in the presentation on conceptual art. It focuses on an explanation about his opposition on aesthetics and formalism with regard to the Wittgensteinian origin of his measurements. For evaluation of what this artist said and what he performed in his artistic  works, we concentrate on the artist’s article entitled “art after philosophy”. We also study and analyze one of his works from series called “one and a few things”. This study shows that Kosuth with relying on “family resemblance” avoids presenting a decisive definition for the concept of art. His research in the conceptual condition of art production leads to the formation of an open concept for Art. So Kosuth hasn’t provided the necessary and sufficient condition for the definition of art. He has created assemblage like “one and three chairs” which is comprised of three parts. One belongs to the definition of a dictionary. The second is a real object in the world. The third is a representational photograph. This whole assemblage is designed equivalent to the proposition “one and three chairs”. So the artist avoids expressing himself, his sentiment, feeling & senses. We conclude that the artist tries to make ready a kind of “state of affairs” for an analytical proposition. This type of proposition doesn’t say anything about the world. It is repetitive. Kosuth shows an advanced and conceptual form of art presentation. He avoids presentation of perceptual, ornamental and optical forms. These kinds of new forms entangled in the enclosed circle of discourse and picture of thought. At last, they aren’t able to go beyond the circle of representation. They neglect to take into account unpredictable effects.