The natural philosopher, in addition to the sensations common to all men inspired by the event of death, believes that he sees with more certainty that it is attended with the annihilation of sentiment and thought. He observes the mental powers increase and fade with those of the body, and even accommodate themselves to the most transitory changes of our physical nature. Sleep suspends many of the faculties of the vital and intellectual principle; drunkenness and disease will either temporarily or permanently derange them. Madness or idiotcy may utterly extinguish the most excellent and delicate of those powers. In old age the mind gradually withers; and as it grew and was strengthened with the body, so does it together with the body sink into decrepitude. Assuredly these are convincing evidences that so soon as the organs of the body are subjected to the laws of inanimate matter, sensation, and perception, and apprehension are at an end.
Percy Bysshe Shelley