In addition to the literal plot of “Dr. Heidegger’s Experiment,” which concerns four elderly individuals drinking water drawn, allegedly, from the Fountain of Youth, the story might also be read as an allegory—in other words, it's a story that operates symbolically. Though the four participants in the experiment conducted by Dr. Heidegger are drawn from very different walks of life, including business, politics, and the military, they aren’t very clearly distinguished, and they tend to act as one. Hawthorne gives little priority to the specific character traits and individual backgrounds of these characters because their role in the story is, to some degree, symbolic. Their joy upon being restored (so they believe) to youth symbolizes the much broader cultural glorification of youth, and their horror upon being “restored” to their true age likewise symbolizes the common fear of aging. When they believe themselves to be young, their behavior is mindless, chaotic, and silly, casting doubt on the assumption that youth is a superior state of being.
In comparison, Dr. Heidegger represents a more positive attitude towards aging and the passing of time. When the effects of the water upon his rose fades, returning it to its original aged state, he insists that he loves it no less than he did when it was fresh; both youth and seniority have their own distinct appeal for the doctor. He also decides, based on what he has observed of the experiment, never to drink from the Fountain of Youth. “If the fountain gushed at my very doorstep,” he claims, “I would not stoop to bathe my lips in it [...].” The doctor, then, represents a different attitude towards aging in the allegory of the story: an acceptance of the inevitability of getting older. The story suggests that to fight against time, as the other characters do, is impossible. The effects of the elixir fade, but so too does natural youth, and their desperate search for the Fountain of Youth is likely to consume their final years.