This excerpt is from Michael Pollan's, The Botany of Desire: A Plant's-Eye View Of The World

Sweetness is a desire that starts on the tongue with a 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 part 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 processed 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.

Start with taste. Imagine a moment when the sensation of honey or sugar on the tongue was an astonishment, a kind of intoxication. The closest I've ever come to recovering such a sense of sweetness was secondhand, though it left a powerful impression on me even so. I'm thinking of my son's first experience of sugar: the icing on the cake at his first birthday. I have only the testimony of Isaac's face to go by (that, and his fierceness to repeat the experience), but it was plain that his first encounter with sugar had intoxicated him-was in fact an ecstasy, in the literal sense of that word. That is, he was beside himself with the pleasure of it, no longer here with me in space and time in quite the same way he had been just a moment before. Between bites Isaac gazed up at me in amazement (he was on my lap, and I was delivering the ambrosial forkfuls to his gaping mouth) as to exclaim, "Your world contains this? From this day forward I shall dedicate my life to it." (Which he basically has done.) And I remember thinking, this is no minor desire, and then wondered: Could it be that sweetness is the prototype of all desire?

Anthropologists have found that cultures vary enormously in their liking for bitter, sour, and salty flavors, but a taste for sweetness appears to be universal. This goes for many animals, too, which shouldn't be surprising, since sugar is the form in which nature stores food energy. As with most mammals, our first experience of sweetness comes with our mother's milk. It could be that we acquire a taste for it at the breast, or we may be born with an instinct for sweet things that makes us desire mother's milk.

Either way, sweetness has proved to be a force in evolution. By encasing their seeds in sugary and nutritious flesh, fruiting plants, such as the apple hit on an ingenious way of exploiting the mammalian sweet tooth: in exchange for fructose, the animals provide the seeds with transportation, allowing the plant to expand its range. As parties to this grand co-evolutionary bargain, animals with the strongest predilection for sweetness and plants offering the biggest, sweetest fruits prospered together and multiplied, evolving into the species we see, and are, today. As a precaution, the plants took certain steps to protect their seeds from the avidity of their partners: they held off on developing sweetness and color until the seeds had matured completely (before then fruits tend to be inconspicuously green and unpalatable), and in some cases (like the apple's), the plants developed poisons in their seeds to ensure that only the sweet flesh is consumed.

Desire, then, is built into the very nature and purpose of fruit, and so, quite often, is a kind of taboo. The vegetable kingdom's lack of glamour by comparison (whoever heard of a forbidden vegetable?) can be laid to the fact that a vegetables reproductive strategy doesn't turn on turning animals on.