The Pursuit of Simplicity (1981), p. 151
Variant: Total security has never been available to anyone. To expect it is unrealistic; to imagine that it can exist is to invite disaster. I believe the most important aim for humanity at present is to avoid war, dictatorship, and their awful consequences.
Better a Shield Than A Sword : Perspectives On Defense And Technology (1987), p. 241
Context: The preservation of peace and the improvement of the lot of all people require us to have faith in the rationality of humans. If we have this faith and if we pursue understanding, we have not the promise but at least the possibility of success. We should not be misled by promises. Humanity in all its history has repeatedly escaped disaster by a hair's breadth. Total security has never been available to anyone. To expect it is unrealistic; to imagine that it can exist is to invite disaster. What we do have in our technological capacities is an opportunity to use our inventiveness, our creativity, our wisdom and our understanding of our fellow beings to create a future world that is a little better than the one in which we live today.