Complex sentence: Alexander has come to believe that patterns themselves are not enough, and that one needs a "morphogenetic" understanding of the formation of the built environment; he has published his ideas in the four-volume work "The Nature of Order".
Split into simpler sentences: Alexander has come to believe that patterns themselves are not enough, and that one needs a "morphogenetic" understanding of the formation of the built environment. He has published his ideas in the four-volume work "The Nature of Order".