However, consideration is a doctrine that flows from the common law and can be suspended according to the principles of justice. Historically, England had two separate judicial systems, and the Courts of Chancery, which derived their ultimate authority from the king over the Lord`s chancellor, prevailed over the Common Law Courts. The same has been true of its principles of equality since the merger of the systems in 1875.  The doctrine of waiver of guilt states that when one person gives an assurance to another, the other relies on him, and it would be unfair to reconsider the assurance, that person is deterred from it: an analogue of the maxim that no one should benefit from his own injustice (nemo auditur propriam turpitudinem allegans). The Court of Appeal went further in a recent debt repayment case, Collier v. P&M J Wright (Holdings) Ltd. Arden LJ, arguing that a partner who had been assured that he should repay only one-third of the partnership`s debt instead of being jointly and severally liable for the whole had relied on insurance through repayments. and it was unfair for the financial corporation to later demand full repayment of the debt.