An agreement is the consent of two or more persons to form some engagement, or to rescind or modify and engagement already made. Dusrum vel plurium in idem placitum consensus. That kind of agreement, the object of which is the formation of an engagement, is called a contract.
Robert Joseph Pothier
January 9, 1699 – March 2, 1772 A treatise on the law of obligations or contracts, vol.1, 1806.
see also Intention To Create Legal Relations
see also Tort