The best account on consciousness i've read so far.
Damasio addresses the problem from a biological and evolutionary perspective and show us that consciousness is not the monolith we are used to think of: rather, it comes in many stages, core and extended.
Under both these two kind there's another level, the 'protoself': an automatic and uncoscious representation held in our brains of everything that happens in our body. This mechanism has the primary role of mantaining the homeostatis, an essential state of equilibrium of our chimical internal state, thus providing a primitive stage for consciousness in the form of a unitary though ever-changing scheme of the organism.

The trick of consciousness happens when we are involved in knowing something.
We have both the sensory cortices of our brain elaborating the characteristics of the object, and the structure of the protoself detecting the changes our organism undergoes in the processing of the object (these may be emotional responses, changes to permit a better elaboration of the input).
At this point, the brain elaborate a second-order 'map', a representation which holds both the object processing and the body engaged in the knowing.
It's simple as that.

But this is not the whole picture: here arise a lot of incomprehension in those who hold skeptical opinions on the explanation of consciousness.
The kind described above is the core version of consciousness, owned by a large number of animal species.
It's a simple though very effective survival device because it develops an individual perspective in the organism, an ability to locate itself in its environment and think of innovative strategies for react to possible threats (way better than an unconscious emotional response as fear or rage).
This knowledge though is restricted to the 'here and now': it's the kind owned by a fox, an eagle or a baby.

What makes us human is extended consciousness.
Our brain and their amazing processing power allow us to develop a huge number of memories through all our life, unique facts of which we became conscious.
Extended consciousness springs up when, beside the world we face each instant, we keep continously in mind memories pertaining our identity, our plan for the future, our recent and ancient past.
Only then we could say that 'we' are doing something, that our actions have a meaning.
If someone's afraid that despelling consciousness would throw away our uniqueness as human beings, it's this second kind of consciousness he want to defend, not the former: and he should not be afraid either, because this vision of human mind is even stronger than every other possible religious weirdness.

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Two more remarks: extended consciousness doesn't need language: it seems that monkeys has it, as well as some other intelligent species (a gleaming example: your dog). However, language amplifies extremely consciousness' potentialities, expanding our identies like tiny big bangs.
Second: Damasio also scolds philosophers who more often than not muddle up the whole thing. In particular, it's a long debated problem that of the impossibility to experience the mind of an another subject only by means of scientific inquiry and objective knwoledge (how does it feel to be a bat?).
This is a logical fallacy rather than a real problem.
The only time that 'be something' and 'know something' coincide is in our personal experience, and i don't see how it could be otherwise: not much of an argument against scientific research, imho. ( )

Pros: interesting topic; good and detailed analysis at times
Cons: very unconvincing; some extremely important arguments are taken for granted and shoddy, which leads to a questionable foundation for further argument; not a good treatment on feeling "self" ( )

Consciousness/Consciousness > Physiological aspects/Emotions > Physiological aspects/Mind and body