Sweetness is a desire that starts on the tongue with the sense of taste, but it doesn’t end there. Or at least it didn’t end there, back when the experience of sweetness was so special that the word served as a metaphor for a certain kind of perfection. When writers like Jonathan Swift and Matthew Arnold used the expression “sweetness and light” to name their highest ideal (Swift called them “the two noblest of things”; Arnold, the ultimate aim of civilization), they were drawing on a sense of the word sweetness going back to classical times, a sense that has largely been lost to us. The best land was said to be sweet; so were the most pleasing sounds, the most persuasive talk, the loveliest views, the most refined people, and the choicest parts of any whole, as when Shakespeare calls spring the “sweet o’ the year.” Lent by the tongue to all the other sense organs, “sweet,” in the somewhat archaic definition of the Oxford English Dictionary, is that which “affords enjoyment or gratifies desire.” Like a shimmering equal sign, the word sweetness denoted a reality commensurate with human desire: it stood for fulfillment.
Since then sweetness has lost much of its power and become slightly . . . well, saccharine. Who now would think of sweetness as a “noble” quality? At some point during the nineteenth century, a hint of insincerity began to trail the word through literature, and in our time it’s usually shadowed by either irony or sentimentality. Overuse probably helped to cheapen the word’s power on the tongue, but I think the advent of cheap sugar in Europe, and perhaps especially cane sugar produced by slaves, is what did the most to discount sweetness, both as an experience and as a metaphor. (The final insult came with the invention of synthetic sweeteners.) Both the experience and the metaphor seem to me worth recovering, if for no other reason than to appreciate the apple’s former power.
from The Botany of Desire: A Plant’s-Eye View of the World by Michael Pollan