“Angels can fly because they can take themselves lightly.”
Chesterton uses levity as a metaphor against swollen self-importance: the ability to take oneself less heavily becomes part of spiritual freedom rather than evidence that serious responsibilities do not matter.
Source details
Orthodoxy, Chapter VII, “The Eternal Revolution,” Project Gutenberg #130. “Angels can fly because they can take themselves lightly” appears inside Chesterton’s explicitly Christian paradox contrasting levity, pride, humility and self-forgetfulness. It remains apologetic and metaphorical religious prose rather than a literal scientific claim about angels, gravity or psychology.