Some philosophers maintain that solving the problem of consciousness is beyond the reach of human intelligence. This is very odd and, I believe, untrue. It fits a sensible intuition that the mind is something special and different, separable from the brain, but the fact that the intuition is sensible does not make it right.
All the natural history required to understand consciousness is now readily available in evolutionary biology and psychology. Gene networks organize themselves to produce complex organisms whose brains permit behavior; further evolution enriches the complexity of those brains so that they can create sensory and motor maps that represent the environments they interact with; additional evolutionary complexity allows parts of the brain to talk to each other (figuratively speaking) and generate maps of the organism interacting with its environment. Within the frame of those interactions, the conversation among the maps spontaneously and continuously tells the "story" of our organism responding to and being modified by the environment. (The story is first told without words and is later translated into language when language becomes available, both in biological evolution and in every one of us.)
This natural knowledge amounts to the emergence of a basic self, and its presence changes the status of the brain's sensorimotor maps from nonconscious mental patterns to that of conscious mental images. Constructed knowledge is a solution to the problem of consciousness. It does not require a homunculus in the control room of the mind and is not scientifically harder to imagine than the long march from genes to culture.
Damasio is director of the Brain and Creativity Institute at the University of Southern California, Los Angeles