In the civil law. The agreement between the two parties to a contract upon the sense of the contract proposed. It is an essential part of the contract, following the pollicitation or proposal emanating from the one. and followed by the consension or agreement of the other. Conventio privatorum non potest publico juri derogare. The agreement of private persons cannot derogate from public right, i. e., cannot prevent the application of general rules of law, or render valid any contravention of law. Co. Litt. 166a; Wing. Max. p. 746, max. 201.