Contracts founded on a consideration which is contra bonos mores are void. See also Merryweather v. Nixan, 2 Smith, L. C. 398, where it was decided that there is no right of contribution between joint tort-feasors. (See Maxs. Nos. 80, 182 and 232.)
83. Exceptio probat regulam. Exception proves the rule.
(See Max. No. 174.)
84. Executio juris non habet injuriam. The execution of the law works no injury. Actus legis neminem est damnosum. The act of the law is hurtful to none.
* 85. Expressio coram quae tacitè insunt, nihil operatur. The express mention of those things which are tacitly implied, has no effect.
A voluntary courtesy is insufficient to support a subsequent promise, unless there has been an antecedent request, and such request must be proved at the trial, except where the consideration, though executed, is of such a nature that it must necessarily have been moved by a previous request, and in which case therefore, such a statement becomes merely “expressio eorum quae tacitè insunt,” and is consequently unnecessary. (Lampleigh v. Braithwait, 1 Smith, L. C. 11th ed. p. 141.)
86. Expressio unius est exclusio alterius. The express mention of one thing causes the exclusion of another.
Where in a mortgage of several properties the following general words were used, “together with all grates, boilers, &c., and other fixtures in and about the said two dwelling-houses and the brewhouse thereunto belonging,” it was ruled that the fixtures in the other mortgaged property did not pass to the mortgagee, although without these words they would have done. By particularising one or more members of a class, an intention may be inferred to exclude the rest.
* 87. Expressum facit cessare tacitum. What is expressed makes what is implied to cease.
The word “demise” in a lease implies a covenant for quiet enjoyment, but if such covenant be inserted, then the maxim will not apply. Implied contracts in law exist only where there is no express promise between the parties. (See Chitty on Contracts, 16th ed. pp. 47 and 385.)