Federal Question Jurisdiction and Justice Holmes‪.‬

INTRODUCTION A recurring issue in the study of federal courts is what cases arise under federal law for purposes of [section] 1331. (1) The general rule is clear enough. The federal issue must arise on the face of the plaintiff's well-pleaded complaint. There are two categories of such cases. One consists in causes of action created by the Constitution or federal law, such as rights of action under the antitrust laws. Another category comprises state causes of action with substantial and contested federal ingredients. The late Paul Bator referred to these categories respectively as "Proposition A" and "Proposition B" cases, terminology that was incorporated into the third edition of Hart & Wechsler's federal courts text. (2)