Concepts, Benjamin Cardozo has said, "are useful, indeed indispensable, if kept within their place. We will press them quite a distance. . . . A time comes, however, when the concepts carry us too far, or farther than we are ready to go with them, and behold, some other concept, with capacity to serve our needs is waiting at the gate. 'It is a peculiar virtue of our system of law that the process of inclusion and exclusion, so often employed in developing a rule, is not allowed to end with its enunciation, and that an expression in an opinion yields later to the impact of facts unforeseen.' "

If Justice Cardozo was here setting forth more than a description of how the "philosophical" or "logical" method ideally should reach its conclusions, he was guilty of overoptimism. That the law has not yet escaped the "tyranny of concepts" is nowhere more clear than in its treatment of the unincorporated association. On the one hand the unincorporated association can be conceived of as an entity, a legal unit as distinct from the members who make it up as a corporation is from its stockholders. On the other hand the association can be regarded as a mere aggregate, a group of individuals similar to a family or a crowd and having no independent legal existence. For years the entity and the aggregate concepts struggled for supremacy while many questions of policy depended upon the outcome. Judges too often neglected to weigh the practical consequences of a decision, and instead deduced the outcome from their resolution of the philosophic controversy.