INTito v. Waddell (No. 2), Megarry V.-C. famously described, and differentiated, the two dealing rules, the “self-dealing rule” and the “fair-dealing rule”, that apply to those occupying fiduciary positions: The self-dealing rule is … that if a trustee sells the trust property to himself, the sale is voidable by any beneficiary ex debito justitiae, however fair the transaction. The fair-dealing rule is … that if a trustee purchases the beneficial interest of any of his beneficiaries, the transaction is not voidable ex debito justitiae, but can be set aside by the beneficiary unless the trustee can show that he has taken no advantage of his position and has made full disclosure to the beneficiary, and that the transaction is fair and honest.