This sure sounds familiar, but that fact did not help me to find it.
Writing,the art of communicating thoughts to the mind through the eye, is the great invention of the world...enabling us to converse with the dead, the absent, and the unborn, at all distances of time and space.
~ Lincoln, from a lecture before the Springfield Library Association, 22 February 1860.
"Oh, the comfort, the inexpressible comfort of feeling safe with a person, having neither to weigh thoughts nor measure words, but pouring them all out, just as they are, chaff and grain together, certain that a faithful hand will take and sift them, keep what is worth keeping, and with a breath of kindness blow the rest away."
~ Dinah Craik (aka: Dinah Maria Mulock Craik) (1826 - 1887) English novelist.