When the minds of two people meet on any subject, is there an agreement?

Flashback to Contracts class! Generally there must be an offer, an acceptance, and some sort of consideration to create an agreement/contract. The consideration can be payment for the goods or services or it can be one party who has a right to do something agreeing to not do it (or the alternative one party has no obligation to do something but agrees to do it). There are certain types of agreements which have to be written on paper, signed, and possibly notarized, such as the sale of land or the grant of power of attorney or an agreement that will take more than a year to come to completion. Some people aren't allowed to make agreements, such as minors or adults who are incompetent. Even agreements made between competent persons may not be enforced, such as when one party commits fraud or takes advantage of the other party in an especially egregious way.

For a contract to exist, there must be (1) an offer, (2) an acceptance of the offer, and (3) some consideration exchanged. The simplest example of a contract is "I will sell you my car for $6000" (an offer). If you accept the offer, you must advise me that you accept. Otherwise, I might sell the car to someone else. The acceptance must mirror the terms of the offer. If you counter with, "How about $5500?" you have rejected my offer. The "consideration" is the part that distinguishes a contract from a gift. It involves your promise to pay for the car if I don't sell the car to someone else. Some contracts need to be in writing. For example, any contracts involving the purchase or rental of property must be in writing. This varies from state to state. It may be advisable for you to consult with an attorney. Many have free initial consultations. Good luck and I hope that this helps.

Maybe yes - but such a meeting of the minds may not have any legal effect.