6 ideas
Sensory responses began as overt bodily wriggles directed at stimuli on the body surface, then became privatized: the motor command was short-circuited so it targets the body's own sensory map rather than the actual skin. This self-referential feedback loop, which Humphrey calls an ipsundrum, creates a sensation that is about the organism's own act of responding, and this is where phenomenal feel originates.
Phenomenal consciousness is not a transparent readout of reality but a theatrical illusion the brain produces for its own consumption. The show is designed to seem to have impossible, other-worldly qualities (the 'thick moment' of present feel, ineffable qualia), and it is this apparent magic, not any information content, that makes it seem so hard to explain.
The selective advantage of phenomenal experience is motivational rather than computational: feeling the world's sensory richness makes existence enchanting and gives creatures a reason to want to stay alive. Conscious beings value their own survival more intensely and invest more in self-preservation and future-oriented projects because being alive feels like something worth having.
Consciousness gives the subject a sense of being a metaphysically special self, an enduring phenomenal presence that seems to transcend the physical body. Seen this way, beliefs in souls, afterlives, and the sacredness of persons are downstream effects of the brain's self-presentation, and they boost self-regard and investment in one's own future.
Once individuals experience themselves as conscious selves, they construct a cultural environment of art, ritual, spirituality, and shared meaning built around that experience. This soul niche then feeds back into selection and development, rewarding and deepening the capacity for phenomenal experience and making humans unusually committed to their inner lives.
Because phenomenal consciousness has a motivational function, attribute it to animals that show behaviors it would produce: sensation-seeking and play for its own sake, curiosity about novel sensory experiences, and a strong sense of self worth protecting. On this criterion, mammals and birds likely qualify, whereas insects and other animals that respond to stimuli without seeking or savoring experience likely lack it.