|•||The invention must have utility.|
|•||The claims must be definite.|
|•||The specification must enable the practice of the invention and must disclose the inventor's best mode of practicing the invention.|
|•||The claimed invention must be novel—that is, it must be new and nonobvious in comparison to the prior art.|
In spite of the examination process, patents are sometimes issued that fail to meet these fundamental requirements. This is not always the fault of the Patent Office. For example, the Patent Office cannot judge whether a claim is novel in comparison to an earlier product if, as not infrequently occurs, the Patent Office is not even aware of the earlier product. Moreover, patent examination is not a practical forum for inquiring into certain questions, such as whether the information disclosed in a specification really reflects the applicant's “best mode.” Questions like these can be explored effectively only in an adversarial proceeding. For all of these reasons, courts have the
1See Section 5.1.