A young maiden will laugh as a tender flower will blow - ay, and a lad will like her the better for it; just as the same blithe Spring that makes the young birds whistle, bids the blithe fawns skip.
-- Sir Walter Scott, Woodstock; or, The cavalier
Scientific American has estimated that development of a machine with self-awareness is very likely by the year 2050. Robin Hanson questions whether they really believe this because they were relatively blithe about the prediction, considering the unpredictable, but immeasurable, impact.
Blithe stems from a Germanic root, blidi, "happy." The sense of the word has shifted from the outward expression of joy to the description of an interior state.