The light that shines into man’s heart is not of man, and must ever be distinguished both from the conscience which it enlightens and from the natural faculty of reason which, when unsubjected to its holy influences, is, in the things of God, very foolishness. As the eye is to the body, so is conscience to our inner nature, the organ by which we see; and as both light and life are essential to sight in the natural eye, so conscience as the inward eye cannot see aright without the quickening and illumination of the Spirit of God.

Yearly Meeting in London, 1879