Fashionable intellectual belief is that reality is plastic, that is it can be formed into whatever people desire it to be. That is the basis for all of the 'isms' from the 19th and 20th centuries. In contrast, God tells us that reality is elastic. That means that it can be pushed out of shape for a while, but it eventually snaps back. The farther it is stretched, the more violent the snap. In Leviticus 19-20 Moses tells Israel to keep separate from the nations and not to adopt their ways. There he gives a set of principles to insure that Israel's society stays within safe elastic limits.