Ind. Code § 26-1-1-103

Sec. 103. Unless displaced by the particular provisions of IC 26-1, the principles of law and equity, including the law merchant and the law relative to capacity to contract, principal and agent, estoppel, fraud, misrepresentation, duress, coercion, mistake, bankruptcy, or other validating or invalidating cause, shall supplement the provisions of IC 26-1. Formerly: Acts 1963, c.317, s.1-103. As amended by P.L.152-1986, SEC.112.