Particle physics is now in a particularly fertile and yet bewildering period. Never before has there been such predictive power as resides in the Standard Model, which proves to be ever more successful as each new result comes in from the highest energy colliders, as well as from low energy precision electroweak studies. Nevertheless, as the concurrence of theory and experiment extends, the puzzles of the Standard Model deepen. The Particles and Fields ‘91 Conference occurred at a time of consolidation of perspectives as well as at a time of searching for new ways to expand fundamental knowledge.