Moralistic fallacy

The moralistic fallacy is the informal fallacy of assuming that an aspect of nature which has socially unpleasant consequences cannot exist. Its typical form is "if X were true, then Z would happen! Thus, X is false", where Z is a morally, socially or politically undesirable thing. What should be moral is assumed a priori to also be naturally occurring. The moralistic fallacy is sometimes presented as the inverse of the naturalistic fallacy. However, it could be seen as a variation of the very same naturalistic fallacy; the difference between them could be considered pragmatical, depending on the intentions of the person who uses it: naturalistic fallacy if the user wants to justify existing social practices with the argument that they are natural; moralistic fallacy if the user wants to combat existing social practices with the argument of denying that they are natural.