It is clear that everything which can be said beforehand about the form of all propositions at all can be said on one occasion. For all logical operations are already contained in the elementary proposition. For "fa" says the same as "(x) . fx . x=a". Where there is composition, there is argument and function, and where these are, all logical constants already are. Si potrebbe dire: One could say: the one logical constant is that which all propositions, according to their nature, have in common with one another. That however is the general form of proposition. 5.471 (1)  The general form of proposition is the essence of proposition. 5.472    The description of the most general propositional form is the description of the one and only general primitive sign in logic. 5.473 (3)  Logic must take care of itself. A possible sign must also be able to signify. Everything which is possible in logic is also permitted. ("Socrates is identical" means nothing because there is no property which is called "identical". The proposition is senseless because we have not made some arbitrary determination, not because the symbol is in itself unpermissible.) In a certain sense we cannot make mistakes in logic. 5.474    The number of necessary fundamental operations depends only on our notation. 5.475    It is only a question of constructing a system of signs of a definite number of dimensions - of a definite mathematical multiplicity. 5.476    It is clear that we are not concerned here with a number of primitive ideas which must be signified but with the expression of a rule.