 In both academic and nonacademic discussions, people often confuse the common good with a public good or a set of public goods. But it is important to keep the two ideas distinct. The facilities that make up the common good resemble public goods because they are often facilities that are supposed to be open and available to everyone (e.g., a public library). This means that it is not possible to exclude those who do not contribute from enjoying the benefits. Nonetheless, the facilities that make up the common good are conceptually different from public goods because these facilities may not be a net benefit for each member of the community. The facilities that make up the common good serve a special class of interests that all citizens have in common, i.e., the interests that are the object of the civic relationship. But each citizen will have various private interests in addition to these common interests, so for any particular citizen, the private interests affected by some facility may be more important from the standpoint of her egoistic rationality than the interests that belong to the special class of common interests. As such, the facility may not be a net benefit to her.