Contract; formation; insufficiency of past consideration.
Facts: Roscorla bought a horse from Thomas at an auction. After purchasing it, Roscorla spoke with Thomas and 'in consideration of the sale' obtained a promise from Thomas that the horse was 'sound and free from vice'. In fact, the horse was vicious and unmanageable.
Issue: Was the promise made by Thomas after the auction that the horse was 'sound and free from vice' a legally enforceable promise?
Decision: The promise was not legally enforceable.
Reason: Although the promise was said to be made 'in consideration of the sale', it was made after Roscorla had bought the horse. The consideration Roscorla offered was therefore past consideration, and insufficient to make Thomas's promise legally binding, in accordance with the rule that 'past consideration is not good consideration'.