Most
people think that shadows follow, precede, or surround beings or objects. The
truth is that they also surround words, ideas, desires, deeds, impulses and
memories.
— Elie
Wiesel, writer, Nobel laureate (b. 1928)
There
are two kinds of light — the glow that illuminates, and the glare that obscures.
—
James Thurber, writer and cartoonist (1894-1961)
Shadow
is the absence of light, merely the obstruction of the luminous rays by an
opaque body. Shadow is of the nature of darkness. Light [on an object] is of
the nature of a luminous body; one conceals and the other reveals. They are
always associated and inseparable from all objects. But shadow is a more
powerful agent than light, for it can impede and entirely deprive bodies of
their light, while light can never entirely expel shadow from a body, that is
from an opaque body.
— From
the Notebooks of Leonardo da Vinci
(1565, page 119)