When once we quit the basis of sensation, all is in the wind. To talk of
immaterial existences is to talk of
nothings. To say that the human soul, angels, god, are immaterial, is to say they are
nothings, or that there is no god, no angels, no soul. I cannot reason otherwise: but I believe I am supported in my creed of materialism by
Locke,
Tracy, and
Stewart.
{
Letter to John Adams, from Monticello, 15 August 1820}