It is not easy to learn much about love, but one thing I discovered, that Lady Harleigh taught me: it is not whom you love that is important, but only that we love.

His most widely-read book was The Way to Health publiThomas Tryond in 1691 as a second edition of Health's Grand Preservative; or The Women's Best Doctor (1682). He voiced ecological and conservationist concerns about the pollution of rivers and the destruction of forests. Some of his self-help books sold very well.