X farmed a land with Ps and was the sole trustee. He sold the land to D but, unbeknown to D, was of unsound mind. Ps sought to have the agreement set aside on the ground of equitable fraud. Privy Council denied this, as the same standards of equitable fraud applied to a person who was ostensibly sane to a person who was in fact sane. There was nothing wrong with D’s conduct. There was no unconscionable bargain since there was no taking advantage etc.