James Smith and Harry Rolle entered into a contract for work to be done on Rolle's house. Rolle paid Smith fifty percent of the total contract before the work started. Before entering into the contract Smith was seen having a few drinks with his friend at the corner bar and was acting in drunken stupor. Rolle refused to pay James monies owed after he completed his portion of the contract claiming that he was under the influence of alcohol when he entered into the contract. After signing the contract he sub - contracted a portion the work to Samuel Stuart paying him fifty percent. Samuel was big in stature but was only 17 years old. The work contracted Samuel  was never completed and he refused to return monies paid.

Explain in relation to contract law.