No, autumn is not always heaven on earth. The season does induce a quickening of the blood and a heightening of humankind’s sensual pleasures. Yet the very jubilant excesses that ensue often lead, at last, to the well-known post-Thanksgiving "holiday blues." In darker ways still, fate and tragedy have made some American Novembers seem more cruel than April. Autumn is honest, it does not pretend to be heaven. Yet almost everybody recognizes that the season’s character transcends those familiar bracing days, crystal nights, bigger stars, vaulted skies, fluted twilights, harvest moons, frosted pumpkins and that riotous foliage that impels whole traffic jams of leaf freaks up into New England (even though Columnist Russell Baker has reminded them that "if you’ve seen 1 billion leaves, you’ve not seen them all"). What is not widely recognized is that autumn is richly enhanced simply by what it is not. Specifically, it is not summer, winter or spring.