As long as man was small in numbers and limited in technology, he could realistically regard the earth as an infinite reservoir, an infinite source of inputs and an infinite cesspool for outputs. Today we can no longer make this assumption. Earth has become a space ship, not only in our imagination but also in the hard realities of the social, biological, and physical system in which man is enmeshed.

Political conflict rests to a very large extent on a universal ignorance of consequences, as the people who are benefited by any particular act or policy are rarely those who struggled for it, and the people who are injured are rarely those who opposed it.

The future is bound to surprise us, but we don't have to be dumbfounded.

If a totally new image is to come into being however, there must be sensitivity to internal messages, the image itself must be sensitive to change, must be unstable, and it must include a value image which places high value on trials, experiments, and the trying of new things.

Perhaps the most difficult ethical problem of the scientific community arises not so much from conflict with other subcultures as from its own success. Nothing fails like success because we don't learn from it. We learn only from failure.

Justification, in terms of the broadening of freedom, for any particular form of institution of property must be argued in terms of whether the losses caused by the restrictions imposed are greater or less than the gains derived from the elimination of costly conflict.

[Peace praxis is] a peace process that deals with conflict integratively.