The mathematics clearly called for a set of underlying elementary objects-at that time we needed three types of them-elementary objects that could be combined three at a time in different ways to make all the heavy particles we knew. ... I needed a name for them and called them quarks, after the taunting cry of the gulls, "Three quarks for Muster mark," from Finnegan's Wake by the Irish writer James Joyce.

I think also of my colleagues in elementary particle theory in many lands, and feel that in some measure I am here as a representative of our small, informal, international fraternity.

Today the network of relationships linking the human race to itself and to the rest of the biosphere is so complex that all aspects affect all others to an extraordinary degree. Someone should be studying the whole system, however crudely that has to be done, because no gluing together of partial studies of a complex nonlinear system can give a good idea of the behavior of the whole.

Sustainability is living on nature's income rather than living on its capital.

When you think you're listening to several conversations at once, they tell me, you may really simply be time sharing - that is, listening a little bit to this one, a little bit to that one

Both biological and cultural diversity are now severely threatened and working for their preservation is a critical task.

If we look at the way the universe behaves, quantum mechanics gives us fundamental, unavoidable indeterminacy, so that alternative histories of the universe can be assigned probability.