Keegan v. Kinnaire

We are of opinion that the court below erred in admitting the witnesses for the plaintiff to testify to conversations which were had between the parties before and at the time of the execution of the written lease given in evidence, and tending to show a particular collateral purpose for the making of such lease; and that John Keegan, one of the lessees, had no actual interest in the demised premises, and was but a formal party.

The rule is recognized by all courts, that where parties have deliberately put their engagement in writing, in such terms as import a legal obligation, without any…