This splendid bit of extravagance, mainly out of Cassio's youthful, ardent gallantry, is, customarily with Shakespeare, tempered by proper awareness, a "seems" or "as if" condition--that is, stormy seas "as having sense of beauty." But first they are "traitors," "ensteeped
" with passion "to enclog the guiltless keel." (The ship is also of pathos, if in reverse.) Ironically enough, whatever the effect of her beauty on nature, Desdemona will not be sufficiently divine to change that ensteeped
, human traitor Iago; on the contrary, her beauty and her innocence will mainly serve to goad his "mortal nature." Unlike the sea, he is indeed human so that, recognizing that beauty and purity, he must hate it for its lack in him, must prove it false, so destroy it.