Part of a special section on ecology in art and architecture. The writer considers the architectural theories of Martin Heidegger and Christopher Alexander in relation to the tradition of process thought. Process thought was a form of post-mechanistic science whose foundations were laid by Schelling, in which nature is seen as, first and foremost, "productivity" or process, and only derivatively as "products" or things. When Heidegger is reinterpreted as part of the tradition of process thought deriving from Schelling, the notion that art generally, and architecture in particular, might play a fundamental role in engendering a superior ethos or way of dwelling in the world (a suggestion repudiated by the philosopher) becomes justified. Alexander, for his part, has attempted to develop an approach to architecture that focuses on living processes, and has been led to examine not only the order underlying all that we build, including cities in all ages, but all that grows throughout nature. Opposing the underlying mechanistic assumptions that, he contends, pervade modernist architecture, he has aligned himself with the tradition of process thought and with post-mechanistic science, claiming that architecture can now play a leading role in developing this new understanding of the world.