The issues raised in this Symposium are of great interest and timeliness. During the 1940s and 1950s, the Supreme Court explored the role of Section 2 of the Sherman Act as an essential element in the antitrust regime. As was true with antitrust generally, courts expanded the reach of Section 2, frequently concluding that the complained-of conduct constituted unlawful monopolization or attempts to monopolize, and approving injunctions forbidding the continuation of exclusionary or predatory practices and orders leading to the breakup of the monopoly itself. However, after the Grinnell decision in 1966, and the Otter Tail case almost a decade later, the Supreme Court seemed to strike Section 2 from its agenda. Finally, in the Aspen Skiing case in 1985 and the Matsushita decisions this year, the Court has resumed grappling with some of the thorny issues raised by Section 2.