11

An obligation of a contract is a
performance which the law
recognizes. If the remedy cuts down
the enforcement materially it impairs
the obligation of contract. So a law
increasing the obligation of a contract
is unconstitutional. (There is a conflict
here, but Ribble believes the view
sound). A number of these
provisions are also governed by the
law saying there shal be no taking
of property without due process of
law.

[Evidence]
(1) A — B (Deed parol agreements inadmissible)
(2) Later statute admitting parol evidence
This is not a law impairing the
obligation of contract. The obligation
exists — so the law that makes for
clear proof is not unconst.
But if you reverse this case,
(1) St. admits parol evidence (2) Law passed
that is inadmissible does impair
the obligation of contract.