This is one of those books that manages to crystallize half-thought-out ideas and insights that you have but never really manage to develop. And once you get your head around the central ideas you can see how applicable these are in many different bits of the world. Obviously, it all about metaphors, and the early chapters of the book look at the types of metaphors we use and how prevalent they are. This stuff alone is really worth a read just to make yourself aware of just how often we use metaphors, but also how we use many different expressions of the same underlying metaphor. Take the following example from the book:
"Theories (and arguments) are buildings:
"Is that the foundation for your theory? The theory needs more support. We need some more facts or the argument will fall apart. We need to construct a strong argument for that. I haven't figured out yet what the form of the argument will be. Here are some more facts to shore up the theory. We need to buttress the theory with solid arguments. The theory will stand or fall on the strength of that argument. The argument collapsed. They exploded his latest theory. We will show his theory to be without foundation. So far we have put together only the framework of the theory."
Surprising isn't it that we use lots of different expressions based around one metaphor? That leads on to one of the fundamental arguments in the book - that metaphors are not merely linguistic devices, they are conceptual. We don't just use the 'theories are buildings' metaphor to get across our message, we actually think and act in those terms too. This obviously has some pretty major implications for our understanding of 'truth', and indeed the latter part of the book covers this in some detail, particularly the philosophical ramifications.
They also argue that our metaphors are grounded in experience, hence a lot of them are about space, orientation and travel. Think how often you use 'journey' metaphors to describe things, for example. This might be in terms of relationships - we're going our separate ways, the worst is behind us etc - or in terms of work - I personally use the phrase "I'm getting there" a lot in reference to work projects. So really we are perceiving first and describing second in terms of more direct/basic experiences.
The book's afterword is also well worth a read as it describes briefly how metaphor analysis has been applied is various fields from psychology to political science, so if you like the idea there is plenty of other suggested reading material.