  So appealing to the yuck factor can insulate an intrinsic Unnaturalness Argument from the most common objections. It does so, however, at significant cost. By conceding that unnaturalness is not sufficient for wrongfulness while failing to provide any positive argument for thinking that unnaturalness in the particular case of chimeras makes them wrong, the proponent of an intrinsic Unnaturalness Argument is reduced to the bald assertion that chimeras are wrong because they are unnatural. This fails to provide any reasons whatsoever to those who do not already share that view. The many people, then, who think that the unnaturalness of a chimera does not make it unethical to create them are in no way epistemically irresponsible in simply rejecting the argument out of hand. Moreover, the intrinsic Unnaturalness Argument differs from the killing/letting die example given above in a significant way: although it is true that we presently lack any theoretically satisfactory way of distinguishing between the organ transplantation case and the various trolley cases, we can nonetheless go a long way towards explaining why it is wrong to kill a healthy person so that their organs can be transplanted. We can talk about the harm of death, the frustration of future interests, the loss of valuable opportunities, the right not to be killed, and so on. But why think that the mere fact that an activity is unnatural makes it intrinsically wrong, or even provides any reason whatsoever for thinking so? It is hard to even begin to make the case, at least in secular terms. Although some maintain that certain patterns of inference from an “is” to an “ought” are valid (see Thomson 1990, 1–33, for discussion), inferring that something is even prima facie intrinsically wrong from the particular fact that it is not natural certainly seems fallacious. An intrinsic Unnaturalness Argument, therefore, is in a much weaker epistemic position than an argument for the conclusion that it is wrong to kill a healthy person for his or her organs.