»Contract Performance in Money. A Contract Law Approach to the Calculation of Damages«: Using the example of non-performance of the contract of sale, the thesis is developed that §§ 249 ff. BGB, including the dogmatics of damage law, are orientated towards non-contractual liability and the comparable contractual liability for damage to integrity and delay and therefore do not constitute a »general« law of damages. The purpose of liability for damages in lieu of performance as an alternative form of contract performance should be the decisive parameter for assessing the claim.