“I am confident in the belief that there truly is such a thing as living again, and that the living spring from the dead, and that the souls of the dead are in existence, and that the good souls have a better portion than the evil.”

Source: The Phantom of the Opera

Source: The Sound and the Fury

Mrs. Alving, Act II
Ghosts (1881)
Context: I am half inclined to think we are all ghosts, Mr. Manders. It is not only what we have inherited from our fathers and mothers that exists again in us, but all sorts of old dead ideas and all kinds of old dead beliefs and things of that kind. They are not actually alive in us; but there they are dormant, all the same, and we can never be rid of them. Whenever I take up a newspaper and read it, I fancy I see ghosts creeping between the lines. There must be ghosts all over the world. They must be as countless as the grains of the sands, it seems to me. And we are so miserably afraid of the light, all of us.

Canto III, lines 88–89 (tr. Mark Musa).
The Divine Comedy (c. 1308–1321), Inferno

At A Child's Grave (1882)
Context: The dead do not suffer. And if they live again, their lives will surely be as good as ours. We have no fear. We are all children of the same mother, and the same fate awaits us all.
We, too, have our religion, and it is this: Help for the living, hope for the dead.

Plato, Phaedo

Fragment iv.
Golden Sayings of Epictetus, Fragments

Quoted in [Moss, Stephen, Captain Scott centenary: Storm rages around polar explorer's reputation, The Guardian, 28 March 2012, http://www.theguardian.com/uk/2012/mar/28/captain-scott-antarctic-centenary-profile]