Is there a stated freedom to contract?

Question

In the United States (and other countries), there is the notion of the freedom to contract. This is the idea that two people of sound mind have the right to enter into any contract with one another that they wish. The law honors this idea, but places limits on it. For example, unconscionable contracts and certain other contracts that violate public-policy ideals are unenforceable; for practical purposes, such contracts are invalid, as if never entered into. (IANAL.)

I'm wondering about the existence of a freedom-to-contract notion in Jewish law. Specifically:

• Is there a statement of chazal or another authority that, in general, people have the freedom to contract?
• If so, what's the earliest authority to say so? What major authorities have said so? Citations, please.

(The reason I mention, above, the limits on the freedom to contract is to clarify that I'm not asking whether Jewish law recognizes an absolute freedom to contract, one without limits. I know that that's not the case: the rule of onaa is a counterexample, and commenters on this question have listed more, like the prohibition against gambling. I'm asking, rather, about the notion of the freedom to contract, however limited it may be in practice.)

Answer 1

The concept of "freedom of contract" exists in Jewish Law with limitations.

Rambam formulated this concept as follows: "כל תנאי שבממון קיים". He mentions it in numerous places: הלכות אישות, פרק ו, הלכה י, ופרק טז, הלכה ח; הלכות שמיטה ויובל, פרק ט, הלכה י; הלכות מכירה, פרק יג, הלכה ג, ופרק יט, הלכה ח; הלכות שלוחין ושותפין, פרק ב, הלכה ג, ופרק ד, הלכה ג; הלכות מלוה ולוה, פרק יג, הלכה ה, ופרק טו, הלכה ז, ופרק יח, הלכה ב

He mentions it in regards to various kinds of contracts, some which run counter to the standard Torah law, and some which give one side to the contract an extreme advantage over the other side to the contract.

Answer 2

Ofer's answer needs clarifications (it's been almost 6 years):

1. The source is Mishna B"M 7,11 and the discussion in the Gemmorah there:

   כָּל הַמַּתְנֶה עַל מַה שֶּׁכָּתוּב בַּתּוֹרָה, תְּנָאוֹ בָטֵל.
   וְכָל תְּנַאי שֶׁיֵּשׁ מַעֲשֶׂה בִתְחִלָּתוֹ, תְּנָאוֹ בָטֵל.
   וְכָל שֶׁאֶפְשָׁר לוֹ לְקַיְּמוֹ בְסוֹפוֹ,
   וְהִתְנָה עָלָיו מִתְּחִלָּתוֹ, תְּנָאוֹ קַיָּם:

   Anyone who stipulates concerning what is written in the Torah, his stipulation is void. And any condition that is preceded by action, his stipulation is void. And any stipulation that it would have been possible for him to fulfill at the end, but he stipulates it from its beginning, his stipulation is valid.

   THe Gemmorah Kesubos 56a limits the general statement of the Mishna to civil law:

   "ושמעינן ליה לר' יהודה דאמר דבר שבממון תנאו קיים"

   ... we have heard that Rabbi Yehuda said: With regard to monetary matters ... one's stipulation stands."

   Theoretically, this could count as your "freedom of contract".

2. As you rightfully mentioned this rule also has its limitations:

   • A condition that overrides a negative monetary Mitzvah usually does not hold, for example: interest, fraud, different forms of defects and more. This is called "מתנה על מה שכתוב בתורה"

   • A condition that requires transgressing another Mitzvah does not hold, for example: eating pork or breaking Shabbos. The monetary Mitzvos, besides the money part, have the essence of a transgression, for example: one can't agree to hit someone or break his limbs in order to pay him the damages (source B"M ...)

   • Any contract is a subject to Rabbinical decrees and declarations that might override it. Also a local Beis Din has the right similar to the power of the Torah in stipulating [usually local] contracts and invalidating them.

   • Any contract is a subject to interpretations [of a Beis Din]. For example the line: "...the product is defective in general" - the buyer can claim that it was intended to facilitate the sale and not really state the product's quality (see Shu"A C"M ...). I think it is similar to the secular civil law that any contract is subject to interpretations.