These are challenging times for neurosurgery. Although no one can predict our future, great changes are in the wind--many of which we are powerless to prevent. We must all take on added social responsibility, above and beyond that of patient care. The leadership of your organization can only act with the support of active and concerned neurosurgeons who are willing to participate in many programs available to our profession. The individual must personally embrace the leadership standards of Sir William Osler and Harvey Cushing. One of the privileges of giving a presidential address is to pay public homage to those who have been supportive and instrumental in my long professional journey. During my residency, Dr. Dwight Parkinson was my mentor and teacher and set a wonderful standard for the ideal practice of neurosurgery. Decisions were black or white, never gray, with Dr. Parkinson, who left little doubt as to the correct way to handle clinical problems. He was, and continues to be, one of the most incisive, imaginative, innovative scientific minds in neurosurgery, and I owe him a great debt of gratitude. Two other men influenced my neurosurgical development. They are Dr. William Horsey, formerly neurosurgeon at the St. Michael's Hospital in Toronto, and Dr. Peardon Donaghy, with whom I spent a most enjoyable and productive year in Burlington at his microvascular neurosurgical laboratory. These two men demonstrated the humility, warmth, and kindness to patients that cannot be learned by formal study, but comes from observing the example of people who manifest those qualities in their own personality.(ABSTRACT TRUNCATED AT 250 WORDS)