Contract, as we will use that term, ordinarily connotes an agreement between two or more persons—not merely a shared belief, but a common understanding as to something that is to be done in the future by one or both of them. Sometimes, the term contract is used also to refer to a document—the set of papers in which such an agreement is set forth. For lawyers, contract usually is used to refer to an agreement that has legal effect; that is, it creates obligations for which some sort of legal enforcement will be available if performance is not forthcoming as promised. Thus, it will sometimes be necessary to distinguish among three elements in a transaction, each of which may be called a “contract”: (1) the agreement-in-fact between the parties, (2) the agreement-as-written (which may or may not correspond accurately to the agreement-in-fact), and (3) the set of rights and duties created by (1) and (2). Without trying at this point to state a short but comprehensive definition of law (if that were possible), it is perhaps sufficient to suggest that we will be surveying the ways in which such agreements are made and enforced in our legal system—the role of lawyers and judges in creating contracts, in deciding disputes that may arise with respect to their performance, and in fashioning appropriate remedies for their breach.当我们使用“合同”一词的时候，通常是说它是一份存在于两方或三方之间的契约。
它不是一种简单的信任，而是通常理解为合同的一方或双方在将来要去做的某种事情。
有时候，“合同”也用来指一套包括协议的文件。
对于律师而言，合同通常是指具有法律效力的协议，即设置了一种法律义务，当某行为没有按照预先约定的那样去履行时，可以依照合同去依法强制履行。
因此，有时候，在一次交易中，区分三种不同的因素就变得非常必要，这些因素中的每个因素都可以叫做合同：（1）双方之间的事实合同（2）书面合同，它可能与事实合同不完全一致（3）基于前（1）、（2）两项中合同所产生的权利和义务。
在权利义务问题上，如果情况可以允许，我们可做到不用去努力阐明这种短少但包含法律意义的界定情况，那么它就强烈建议我们在早己设定好的合同和现行法律柜架下的去审视在（订立）创制合同中律师和法官的（角色）作用，他们会解决各方行为引发的争执以及对违约行为以恰当的形式进行补偿。
In the Anglo-American legal system, a great number of things—both tangible and intangible—are susceptible of “ownership.” A bull dozer, a diamond ring, the Empire State Building, “Gone With the Wind”—all may be the “property” of one person or group of persons, which means that the state will protect the right of the“owner” to use, enjoy, and even consume that thing, to the exclusion of all other persons. The first-year property course traditionally focuses on the detailed rules that in Anglo-American law govern the ownership of “real property” (land and the buildings on it), as well as some types of “personal” property, such as “goods” (tangible moveable property). Later you will have the opportunity to explore bodies of law relating to ownership of other, less tangible kinds of property such as copyrights, patents, shares of corporate stock, and negotiable instruments.在英美法律体系中，很多事物—有形的和无形的—都涉及“所有权”问题。
一台推土机、一枚钻戒、帝国大厦、小说《飘》，都可能是一个人或者一些人的财产。
这意味着国家将保护所有权人对其所有物的使用、享受甚至是毁灭的权利，同时排除他人对此行为的干涉。
按照惯例，第一年的财产课程会侧重于英美法律对财产保护的详细规定，诸如土地和地上物等不动产的所有权的细化性规定。
然后，你将会学习到基本是对版权、专利权，股权，可转让票据等无形财产的所有权的法律保护。
Any society that recognizes property rights must also address the question of how it should respond when someone violates those rights. And property rights are not the only kind of individual rights that may need legal protection. Even societies that do not permit private ownership of wealth to the degree that ours does are likely to recognize the personal rights of individuals to be free from certain kinds of conduct such as the infliction of physical injury or other interferences with their individual freedom or dignity. The courses in criminal law and torts deal with different aspects of this question: Criminal law focuses on those violations of personal and property rights that society deems serious enough to be deterred by the threat of punishment for their commission (robbery, rape, and murder are obvious examples); tort law considers what remedy should be made available to the individuals so injured. Because of the nature of the conduct regulated, criminal law and tort law overlap to a great degree, but they are not congruent. Many acts are criminal but not tortious, because they are offenses not against individuals but against the state—treason, for example, or tax evasion; others, such as slander, may be tortious but not criminal.任何社会一旦承认财产的所有权，那么它就必须解决如何处置“侵犯财产权”的问题。
财产权不是由法律简单地保护的一种个体性权利。
甚至，社会不允许财产所有权个人肆意同意他人创设某种随意侵害他人身体或其他有损他人个体自由或者尊严的行为的权利。
关于（财产权的保护）这个问题，刑法和民事侵权行为法有自己有不同的规定：刑法侧重于对个人和财产性权利不受妨害的保护，即社会认为这些犯罪行为的危险性已经严重到须以一系列刑罚惩处方可阻止的程度。
比如抢劫、强奸、谋杀都是明显的例子。
民事侵权法则认为对于个体的伤害应给予有效的赔偿。
由行为在本质上的不同，因此，刑法和民事侵权法即使有很大部分是重合的，但二者并不完全相同。
许多行为由于他们侵犯的不是个体而是国家，因此它们属于民事侵权行为而是刑事犯罪，比如，叛国罪、偷税罪；而诸如诽谤则属于民事侵权行为而非犯罪行为。