Henry Drummond FRSE FGS was a Scottish evangelist, biologist, writer and lecturer. He was a friend and contemporary of the Rev. John Watson (the Kailyard novelist Ian Maclaren) at Stirling High School and the University of Edinburgh. Many of his writings were too nicely adapted to the needs of his own day to justify the expectation that they would long survive it, but few men exercised more religious influence in their own generation, especially on young men. His sermon The Greatest Thing in the World remains popular in Christian circles.