But while we know a great deal more about sleep now than when Galen was around, we still haven't understood why it is that sleep, of all of our activities, has this incredible restorative function for the mind.
Pese a que hoxe sabemos  moitísimo máis sobre o sono que cando vivía Galeno, aínda non comprendemos por que o sono, de todas as nosas actividades ten esta incríbel función reparadora  para a mente.