If every signified evoked by reading or hearing any signifier is indeterminate, it makes no sense to formulate a semiotics cum philosophy that attempts to prove the correctness of the proposition that every signified is indeterminate, since that proof uses signifiers.
Those who proclaim as their unshakeable conviction that man (= every human being) is only consciousness, as the most famous structuralists and Derrida with in their wake the deconstructionists do, and that consequently only subjective interpretations of what is true and morally good are possible, proclaim a new version of objectivism, of the doctrine which says that there are certain moral truths which are independent of the individual's attitude to life, that is, of the way in which the individual usually behaves and judges things. Their version of objectivism, like any other form of it, will lead to the formulation of categorical imperatives.