Swans take one mate For life And never change. So too do geese - Out of all birds, this few Constant. And why? The air Is full of bickering Pairs who couple anew each passing spring. In face of such ephemeral delights, Why keep this single flight? Ask swans. Ask geese. Ask air, that brings No answer but The beat of wings. If it's a habit, it's So deeply grafted on the very bone To cut it out, you'd have A wingless bird. No other mate. Together or alone. And whether swans or geese Angels or lunatics Who scribble On the sky With wings, their sole reply, Deeper than feather, deeper than thought or will The single impulse shapes the double flight; Four wings that rise as one And will not be gainsaid By all the bickering birds that clot the sun.