68. First, the reasoning proceeds on the basis that, in certain cases, a settlement between a claimant and one tortfeasor, even though for a lesser sum than would have been awarded on full liability, can have the same effect as a judgment between the claimant and the same tortfeasor in preventing the claimant from suing another tortfeasor for the same injury. Just as the claimant who has been paid the sum of damages awarded by the court for his injuries has everything which he is entitled to and can ask for no more, so, the House held, a claimant who has been paid a sum which was intended to be in full satisfaction of his claim is to be treated as having got everything he is entitled to and cannot ask for any more.