The court's analysis in the case of Lucy v. Zehmer is fairly compelling. Judge Buchanan's analysis to this point, quoting from the Restatements of Contracts, is convincing:
The mental assent of the parties is not requisite for the formation of a contract. If the words or other acts of one of the parties have but one reasonable meaning, his undisclosed intention is immaterial except when an unreasonable meaning which he attaches to his manifestations is known to the other party.
This becomes the critical issue in the case. The mental condition of "jest" or "joking around" is secondary to the issue of whether there were formalities that indicate a contract had been adopted. In the case, while both Lucy and Zehmer were drunk, there was negotiating which indicates a contractual agreement was understood:
The appearance of the contract, the fact that it was under discussion for forty minutes or more before it was signed; Lucy's objection to the first draft because it was written in the singular, and he wanted Mrs. Zehmer to sign it also; the rewriting to meet that objection and the signing by Mrs. Zehmer; the discussion of what was to be included in the sale, the provision for the examination of the title, the completeness of the instrument that was executed, the taking possession of it by Lucy with no request or suggestion by either of the defendants that he give it back, are facts which furnish persuasive evidence that the execution of the contract was a serious business transaction rather than a casual jesting matter as defendants now contend..
The redrafting of the contract, the dependence of the transaction on the examination of the title, as well as length of time in discussing the contract were all points that the court used as reference to determine that the contract was an actual contract. It is in this where I think that the court's points were compelling in their decision. Indeed, while there was plenty of drinking between both parties, business transactions go on and the establishment of the contract takes precedence over a perceived "casual jesting matter." Contracts are legally binding and cannot be dismissed because of "the morning after." In this light, I think that the court was right in its ruling.