Ludwig Wittgenstein and certain of his friends and followers have offered an interesting answer to the question of the relation “one fact (such as a sentence) [must] have to another in order to be capable of being a symbol for that other”. The answer in brief, as Russell puts it, is that, “in order that a certain sentence should assert a certain fact there must … be something in common between the structure of the sentence and the structure of the fact”. Wittgenstein himself in the Tractatus usually denominates this common element as logical structure. The sentence is said to picture its fact; it reflects, mirrors, shows or exhibits by means of its own structure the structure of the fact it is about. Critics and interpreters generally agree with Russell's broad characterization of the theory but disagree greatly as to the exact nature of this postulated common structure. Consequently, the evaluation of the theory which this paper proposes to make must include an examination of its several alternative interpretations.