Keats Against "Cold Philosophy"

...Do not all charms fly At the mere touch of cold philosophy? There was an awful rainbow once in heaven: We know her woof, her texture; she is given In the dull catalogue of common things. Philosophy will clip an Angel’s wings, Conquer all mysteries by rule and line, Empty the haunted air, and gnomed mine - Unweave a rainbow, as it erewhile made The tender-person’d Lamia melt into a shade.