“The rule is, jam tomorrow, and jam yesterday—but never jam today.”“It must come sometimes to ‘jam today,’ ” Alice objected.“No, it can’t,” said the Queen. “It’s jam every other day: today isn’t any other day, you know.”

This exchange occurs in Lewis Carroll’s sequel to Alice’s Adventures in Wonderland, when Alice meets the White Queen in the “Looking-Glass” world. The Queen offers Alice “jam,” but only on the absurd condition that it is available “tomorrow” and “yesterday,” never “today.” The scene is part of Carroll’s broader parody of logic, grammar, and everyday reasoning: the Looking-Glass realm runs on linguistic tricks and inverted rules. Carroll (Charles L. Dodgson), a mathematician and logician, frequently used such comic dialogues to expose how easily language can be made to sound rigorous while producing nonsense conclusions.

The “jam tomorrow and jam yesterday—but never jam today” rule satirizes promises that are perpetually deferred: rewards are always located in an unreachable time, so the offer can never be fulfilled in the present. Carroll also turns on a logical/linguistic quibble—“every other day” excludes “today” because “today isn’t any other day”—to show how wordplay can masquerade as airtight reasoning. The passage has endured as a critique of institutions or ideologies that keep people compliant with future benefits that never arrive, and as a playful illustration of how definitions and categories can be manipulated to deny what seems plainly due.