Agreement further imports that there shall be a mutual communication between the parties of their intentions to agree, for without this neither could know the state of the other's mind. The law, therefore, judges of an agreement between two persons exclusively from those expressions of their intentions which are communicated between them.8 Mere uncommunicated intention, though common to both parties, cannot constitute agreement. If a person asks another if he will do something, and the latter makes no reply, there is no agreement, even though he may intend to do it. A secret acceptance of a proposal cannot constitute agreement; nor, it is said, can agreement result where the intention of a party is communicated, not to the other party, but to a third person." So, the fact that a party has changed his mind after making an offer and does not really intend to contract is of no significance if he does not communicate his change of intention to the other party before acceptance. And if one party has reasonably led the other to believe that he is making an offer the other may, by acceptance, convert such apparent offer into a contract although in fact no offer was intended. In like manner if a person to whom an offer has been submitted makes such statement or does such act with respect thereto as would lead an ordinarily prudent person, acting in good faith, to believe that the proposition had been accepted, and the proposer accordingly acts upon that assumption, a contract results, notwithstanding secret intentions of the offeree not to accept.10 As we shall see, communication may be by conduct as well as by words.