The full quote: “The light dove, in free flight cutting through the air the resistance of which it feels, could get the idea that it could do even better in airless space. Likewise, Plato abandoned the world of the senses because it posed so many hindrances for the understanding, and dared to go beyond it on the wings of the ideas, in the empty space of pure understanding.”
My translation: Dove, the air is not holding you back, it's holding you up. The original is Immanuel Kant, Critique of Pure Reason
there doesn't seem to be anything here