Those who dream by night in the dusty recesses of their minds wake in the day to find that all was vanity, but the dreamers of the day are dangerous men for they may act their dream with open eyes and make it possible.

This sentence is best known as a prefatory reflection by T. E. Lawrence (“Lawrence of Arabia”) in connection with his First World War experience and its aftermath. Lawrence wrote The Seven Pillars of Wisdom as an account of the Arab Revolt and his role in it, shaped by disillusionment with wartime promises and postwar settlements. The line frames the memoir’s themes of imagination, will, and political action: private fantasies dissipate, but deliberate, waking “dreams” can be pursued as programs and made real—sometimes with destabilizing consequences. It is often quoted as a capsule of Lawrence’s view of visionary ambition and its power to alter history.

Lawrence contrasts two kinds of “dreaming.” Night dreams are inert: they dissolve on waking and can be dismissed as vanity. “Dreamers of the day,” by contrast, imagine while awake and can translate vision into action. The “danger” is double-edged: such people threaten the status quo because they may attempt to impose an idea on reality, for good or ill. The sentence captures a modern, voluntarist view of history—events are not only endured but also made—while warning that imagination coupled with agency is a potent, destabilizing force.

1) “All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity; but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible.”
2) “Those who dream by night… wake in the day to find that it was vanity; but the dreamers of the day are dangerous men, for they may act their dream with open eyes, and make it possible.”