(From the preface of a German textbook on animal physiology)
“In the actual world around us,
there is no light or color,
no warmth, coldness, taste, smell or sounds.
Our perceived sensory world is a product.
It is an achievement of our brain.
It is not the passive copy of a real world.”
[Heinz Penzlin – Lehrbuch der Tierphysiologie, 1996, 6. Auflage]