His use of the word detachment is really what we mean by non-attachment in today's meditation terminology.
By detachment I do not mean total flight from life, but rather the achievement of wise perspective -- what Spinoza called "looking at things under the aspect of eternity." Detachment gives us the understanding that we are born into a world that is larger and more important than we; that we are drops in an infinite sea; that we are marvelously distilled globules of Divine rain and dew; that we shall not last forever; that all of our priceless values are at the mercy of time, and that we cannot have both intensity of experience and permanency of duration.By detachment I mean the ability to look at ourselves with a kind of laughing humor, a nodding acquaintance with our fragilities, a tipping of the hat, as it were, to the petulant angers which vanish as we recognize them. By detachment I mean also the daring to view our individual life in the greater setting of time and eternity; to taste beforehand with the tongue of imagination the defeats and the pains to which life commits us, and by so tasting to remove something of the gall and vitriol from the cup of defeat. Man has this gift of discounting both his own victories and his own calamities. Let us utilize it to the full, for our greater peace of mind.