What messed with my mind was DMF's simplistic appeal to Natural-Law doctrine, which I don't think he'd invoke in most contexts, and certainly not with regard to transgender issues. (He may well not have realized he was doing so: he's not the most careful thinker.) Quite apart from the fact this doctrine is a mainstay of antifeminist, antigay and antitrans bigots -- though the Born-Gay argument also relies on it -- it can't be applied consistently to human beings. Nor does anyone do so: I alluded to the apostle Paul's decree that "nature" teaches that women shouldn't cut their hair but men should do so. The passage is a marvel of incoherence, which is what one usually finds when people invoke Nature for any reason, for any cause (via). (It's fascinating to me that some arbitrary religious requirements inspire contempt, while others inspire awe, with no criteria for the difference that I can discern.)
People shouldn't be required to modify their bodies in certain ways, but cutting or shaving hair, trimming nails, covering or uncovering themselves, painting or otherwise adorning themselves, are so ubiquitous in human cultures that such practices can reasonably called "natural," though no particular modification should be mandatory. And anyone who denounces one given modification almost certainly will favor another. Which practices (if any) should be forbidden can only be decided by deliberation and judgment, not by appeals to Nature or any other fixed rule.
