'This book is the product of a conference on intelligence held at the University of Illinois. Ordinarily, the Preference is an appropriate place to thank the contributors...This will be done but it would be less than candid not to say a few words about the climate in which the conference took place. Apprehension, fear, and threats were omnipresent. There was a bomb threat, not to mention a variety of threats of major disruption...It is a testimony to the courage and integrity of the vast majority of students etc... that the conference was held successfully and peacefully.'