Contracts are an important type of "private" law.  Many contracts arise due to gains from trade owing to differences in (i) resources, (ii) valuation, (iii) expectations, (iv) risk-bearing abilities, and (v) production abilities (from economies of scale, special skills, and specialization and division of labor), and complementarities among those abilities. Other contracts respond to restrictions, obligations or entitlements arising from other laws, such as licenses, disclaimers, settlements, formal requirements, and confidentiality obligations. Lawyers play crucial roles in crafting contracts and structuring complex projects, linking "suites" of contracts to coordinate multiple parties over time, against background regulation and contract law. Courts and legislatures interact to produce and redirect common law of contract and specialized rules and standards for subtypes of contracts, which evolve over time and vary across jurisdictions and contract settings.  To do so, they pursue three general goals simultaneously:  (1) enhancing welfare of contract parties (or classes of parties) (sometimes called "efficiency" by economists and lawyer-economists, generally in line with utilitarianism), (2) respecting morality (particularly aspects of individual autonomy, deontological theories of rights, and procedural fairness, but also limits of autonomy and ways that individuals may not be able to protect their own interests), and (3) minimizing costs of administration (sometimes called "administrability" or "system design").  Remedies are central, as well as limits on remedies, with courts inevitably developing and applying public policies due to the common need to find, construct and remedy breaches of contracts.  

Thanks to Alyn Wallace for helpful edits and suggestions on the 2024 version of the book.