Have one's cake and eat it too

You can't have your cake and eat it (too) is a popular English idiomatic proverb or figure of speech. The proverb literally means "you cannot simultaneously retain your cake and eat it". Once the cake is eaten, it is gone. It can be used to say that one cannot or should not have or want more than one deserves or is reasonable, or that one cannot or should not try to have two incompatible things. The proverb's meaning is similar to the phrases "you can't have it both ways" and "you can't have the best of both worlds."

Many people misunderstand the meanings of "have" and "eat" as used here but still understand the proverb in its entirety and intent and use it in this form. Some people feel this form of the proverb is incorrect and illogical and instead prefer "you can't eat your cake and [then still] have it", which is in fact closer to the original form of the proverb (see further explanations below) but uncommon today. Other rare variants use "keep" instead of "have".

Having to choose whether to have or eat your cake illustrates the concept of trade-offs or opportunity cost.

The order of the clauses in the saying has been the subject of some debate, and was even used in forensic linguistics (contributing to the identification and arrest of the so-called Unabomber).

An early recording of the phrase is in a letter on 14 March 1538 from Thomas, Duke of Norfolk, to Thomas Cromwell, as "a man can not have his cake and eat his cake".

The phrase occurs with the clauses reversed in John Heywood's "A dialogue Conteinyng the Nomber in Effect of All the Prouerbes in the Englishe Tongue" from 1546, as "wolde you bothe eate your cake, and have your cake?". In John Davies' "Scourge of Folly" of 1611, the same order is used, as "A man cannot eat his cake and haue it stil." In Jonathan Swift's 1738 farce "Polite Conversation", the character Lady Answerall says "she cannot eat her cake and have her cake."

The order was reversed again in a posthumous adaptation of "Polite Conversation" in 1749, "Tittle Tattle; or, Taste A-la-Mode", as "And she cannot have her Cake and eat her Cake." From 1812 (R. C. Knopf's "Document Transcriptions of War of 1812" (1959) VI. 204) is a modern-sounding recording as "We cannot have our cake and eat it too."

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