Umberto Eco ( Limits of Interpretation ) criticizes Barthes’s notion that connotation occurs when “a sign function (Expression plus Content) becomes in turn the expression of a further content.” He argues that “in order to have a connotation, that is, a second meaning of a sign, the whole underlying first sign is required – Expression plus content.”
“Pig” can mean “filthy person” only “because the first, literal meaning of this word contains semantic markers such as ‘stinky’ and ‘dirty.’ The first sense of the word has to be kept in mind (or at least socially recorded by a dictionary) in order to make the second sense acceptable. If the meaning of pig were ‘gentle horse-like white animal with a horn in its front,’ the word could not connote ‘filthy person.’” Even when a word like pig comes to have this connotation, that use still has to be “legitimated by the context.” (He mentions Disney’s three little pigs who are “neither filthy nor unpleasant,” but I wonder if he’s not missed an important inversion of the connotation here: Is it important to the Disney story that the pigs are contrary to type?)
What Eco says of words goes for larger units. A sentence like “the Pharisees cast him from the synagogue” could not mean “the ‘Pharisees’ cast him from the ‘synagogue’” (applied, say, to the expulsion of a minister from his church) if the first sentence didn’t mean “the Pharisees cast him from the synagogue.” The connection between “Pharisee” and “‘Pharisee’” is not merely expression; the original content of the word is carried into the second sentence as well.