| "What is it like to be a bat" is an essay by the philosopher Thomas Nagel, published in the compilation Mortal Questions. It's an eloquent and imaginative essay on the subjective nature of experience, and a being's experience of the world.
The essay suggests that, though we share some senses in common with the bat, the experience of existence is completely different. This can be extended to be understood that existing and perceiving reality are different for each person as well.
Descartes' ideas on reality and perception make a nice complimentary theory to Nagel's. The thought of the mind as the sole point of concrete reality, and the rest being a perceptual amalgam combined with the idea of seperate conscious minds perceiving things in fundamentally different ways provides a framework for reality that leaves a lot of possibility for variation. | 
