I LOVE this book. Semantics and the Body by Horst Ruthrof is the missing link between post-structuralism and linguistics that I've been waiting for.
The author briefly summarizes the history of philosophy of language before really delving into the nitty-gritty of why traditional formal semantics can't handle essential things like negation and metaphor. It's clear he knows his stuff.
While he doesn't buy post-structuralism hook, line and sinker, he does make an important move that is clearly based on literary theory. Instead of beginning with 'normal' language or 'positive' statements and considering meatphor and negation as marginal phenomena that can be described later (as linguists do), he begins with these as things a philosophy of language must account for, and goes on from there.
Ruthrof does buy the claim that everything is textual. That is, in opposition to Lakoff et al., he doesn't think there's some realm of unmediated physical experience that we code into language via metaphor. He believes the body has an essential place in a theory of language because it is a mechanism for interacting with and encoding various perceptual sign systems. It is these non-verbal modes of signification that make ALL linguistic expressions meaningful.
Metaphor, then, simply highlights the play (and the slippage) between the various systems. There is a continuum from metaphor to literal speech that we must negotiate (with varying degrees of uncertainty) every day. This is a pretty elegant theory. It buys a lot of things (for example) a theory of metaphor that meshes with a theory of literal language, without a lot of the explanatory baggage that Lakoff needs to pull along (does each individual's experience shape their metaphorical domains? what is the role of historical change in moving from 'live' to 'dead' metaphors?).
Pay attention, philosophers of language: these divisions (literal/figurative; live/dead; negative/positive) are not as clear cut as formalism would like them to be. Admitting that is the first step toward getting help.