Some gay political activists wrote the following:
“The a priori (i.e., philosophical) argument suffers from a number of — in my opinion fatal — flaws, depending on how the idea is cashed out. If it is a matter of children having a right to a mixed sex family because that is the natural state of affairs for human beings, then this is an argument based on an appeal to nature, which immediately runs afoul of the obvious objection that we do all sorts of other things to children (from education to vaccination) that is not natural at all, and yet to which only lunatics and Jenny McCarthy would object to. Not to mention, of course, that there are plenty of perfectly natural situations where children either have only one parent or no parent at all around during their upbringing.”
Let us consider the following proposition:
“Is in the nature of men to have beards. So, every man should grow a beard.”
This is a naturalist fallacy, and the following proposition is a naturalist fallacy too:
“Some irrational animals have homosexual behavior; therefore, homosexual behavior in human beings is natural”.
Of course, we are referring here to adults, not to children. The naturalist fallacy only applies to people that have some degree of autonomy of decision: we may not apply ethical mores and values to people who do not have a sufficient capacity of choice and free will.
It is true that the human nature cannot determine ethics. But it is also true that ethics values cannot be naturally and spontaneously assumed by a child. So, as far as adoption is concerned, the focus should be put in the happiness of the child, and not in the happiness of the adults. By shifting the focus from the child to the adults, some people engage in the gay adoption fallacy.