Moral codes adjust themselves to environmental conditions.

The line expresses a broadly anthropological and historical view of ethics: what a society treats as “moral” is not fixed for all times and places, but tends to evolve in response to material circumstances—climate, scarcity or abundance, economic organization, war and security, population pressures, and prevailing technologies. Read this way, morality functions partly as a social adaptation: norms that help a group survive and cohere under particular conditions become sanctified as virtues, while norms that no longer fit changing conditions are revised or discarded. The claim does not necessarily deny moral reasoning or ideals; rather, it emphasizes that moral codes are historically contingent and often track practical needs as much as abstract principles.