What can you conceive more silly and extravagant than to...

What can you conceive more silly and extravagant than to suppose a man racking his brains, and studying night and day how to fly? ... wearying himself with climbing upon every ascent, ... bruising himself with continual falls, and at last breaking his neck? And all this, from an imagination that it would be glorious to have the eyes of people looking up at him, and mighty happy to eat, and drink, and sleep, at the top of the highest trees in the kingdom.