The year now ending has marked the centennial of the founding of the National Academy of Sciences, and in celebration the Academy arranged a four‐day commemorative program during the period from October 21 to 24 in Washington, D.C. The program included the formal presentation of greetings by representatives of other academies, learned societies, and universities, and various social events, including a reception in honor of the Academy's foreign guests given by Secretary of State Dean Rusk. A substantial part of the meeting was devoted to four sessions of invited papers by distinguished members of the Academy. President Kennedy's talk on the second day, just one month before he was brutally slain on November 22, would have been remarkable if only because Chief Executives so rarely address gatherings of scientists. It was all the more so in being a thoughtful expression of national scientific policy and a warm tribute to the Academy, and the text is accordingly given in full in the pages that follow.