This is a book about representation, about how the brain deals with representations. The study of mind has largely taken language as its main reference point. Semantics, for example, is derived from studies on language and semantic theories often reflect the way language works. But language is not the only way we can communicate some meaning. Even if one wants to discount the fact that images are pervasive in nature, today we live in the age of multimedia presentation, where a picture is often preferred to a story. Cognitive Science is good at answering the question "how does the brain process the meaning of a sentence?" but not so good at explaining how the brain processes the meaning of a diagram. Diagrams are routinely used to teach Logic, so we know that diagrams can be as effective as sentences. Some psychologists believe that diagrams are "better" for teaching Logic, but people like me are living exceptions: I always found diagrams very confusing to explain logic, despite the fact that I graduated summa cum laude in Mathematics. In general, the power of diagrams is often overstated. Ultimately, there are cases in which a diagram is no more than a sentence presented in a different (but not necessarily "easier") way. The real difference is that diagrams are often a "direct" representation, whereas sentences are indirect in that syntax (a representation itself) acts as an intermediary between representation and interpretation. Needless to say, people who prefer one system over the other turn out to employ different strategies to solve problems.

Humans have a choice of representations. They tend to choose the one that works best, the one that greatly simplifies the problem for their brain. Basically, representation is about reformulating the problem in a way that makes it very easy to solve. So human reasoning is meta-reasoning about representation systems.

One interesting topic of the book is "what is it that students learn when they study Logic"? If Logic is the foundation of human thought, why do we need to learn it again in school? And why do we make mistakes when we apply it? Shouldn't it come as natural as breathing? As Johnson-Laird first noticed, our brains do not have a function to produce mistakes: then why do we make mistakes? Johnson-Laird answered that brains do not use Logic, they use "mental models", and mistakes are by-products of a very efficient way to represent and reason about the world. Stenning shows, instead, that Johnson-Laird failed to prove that Logic is not what human reasoning is all about. Stenning provides a different answer: it's the discourse that causes all the difficulties. Students have to figure out the "pragmatics" (as per Grice's maxims) of the circumstances, and they have (quite simply) to unpack the terms of the problem from the bundle of natural-language sentences that express it. Therein lies the uncertainty that eventually leads to mistakes in reasoning. If we remove the ambiguity of natural-language sentences, our brains use Logic to solve the problem, and do so in a very efficient way.

The book turns even more interesting once it starts dealing with the way a representation system is implemented in the mind.

Analogical reasoning (which is about finding form in content) sheds some light: analogies are directly interpreted representations. Reasoning is about discovering and creating representations. Analogies are easier to make with narratives that are about human experience, because we easily relate the emotional content of one story to the emotional content of the other one (or the emotional content of one social behavior to the emotional content of another social behavior), and that is the form (the analogy) that we are looking for. Analogies are often difficult to make in the scientific domain because we cannot relate the scientific theory to our emotions, to our human experience. In other words, the analogies that we solve quickly are the ones that we are biologically programmed to solve quickly, thanks to our repertory of emotions and to our understanding of social behavior. The same applies to metaphors. Lakoff's emphasis on bodily features is replaced by Stenning with an emphasis on emotions: we understand a metaphor because the emotions involved are fundamentally the same.

It turns out, thus, that emotions are a way to abstract situations. Similar emotions are used to classify situations and objects into concepts and categories. In a sense, "concepts predate our encounter with particular stories". Semantically speaking, emotions are the ultimate meaning.

Stenning can then easily solve Wittgenstein's famous riddle: we all know what a "game" is, but there is no simple definition of what a "game" is. Stenning thinks that we know what a "game" is because we know what the emotion related to a game is. Anything that elicits the same kind of emotion is a "game". We don't need to find a definition for the word "game".

By the same token, communication is but the articulation of emotions through the development of adequate representations.

By the same token, the reason it is so easy for us to learn something so difficult as language (with all its idiosyncrasies) is that language is structured according to our emotional systems. It reflects the way our emotions work.

Stenning rediscovers an obvious truth: we are not only weird systems that build representations but also weird systems that have emotions about them. His explanation for this oddity is simple: emotions "are" the implementations of those representations in our minds.

Damasio has been reaching similar conclusions about the importance of emotions in guiding reason. Emotional reaction is not an interferece with the logical calculation: it "is" the calculation. Emotional reactions are implementations of reasoning processes. Emotion implements cognition.