Please note: This is a companion version & not the original book.

#1 Consciousness is the most difficult thing to understand. It is both the most obvious and the most difficult thing we can investigate. We seem to have to use consciousness to investigate itself, which is a slightly weird idea.

#2 The mind–body problem is a modern problem that stems from the fact that our experiences seem to be two entirely different kinds of thing. On the one hand, there are our own experiences, which are ineffable and cannot be conveyed to others. On the other hand, there is a physical world out there that gives rise to these experiences.

#3 The most famous dualist theory is Cartesian dualism, which states that the mind and brain are made of different substances. The mind is non-physical and non-extended, while the brain and the rest of the physical world are made of physical, or extended, substance.

#4 The hard problem of consciousness is the difficulty of explaining how a physical brain, made of material substances only, can give rise to conscious experiences or ineffable qualia.