I have undertaken with much hesitation to write a short sketch of my brother's life, as an intro duction to his Gifford Lectures. In doing so, I have to remember that he was a man of much reserve, which even after his death I am bound to respect; and that for a long time my relations with him were so close and intimate, that it is probably impossible for me to see him as others saw him. Also his life was uneventful, and the materials in the way of correspondence which are at my disposal are not large.