When it comes to gene editing of human embryos, we come up against three moral dilemnas. First of all, gene editing is a slippery slope to eugenics. The ability to select for specific genes could be utilized by governments to filter out what they determine to be undesirable traits. Secondly, there's an argument for gene editing when it comes to medical treatment and prevention of genetic disorders and disease and potentially limit human suffering. However, when you get into the practicalities of such gene editing you come up against a massive hurdle. Which diseases, disorders or traits should be eliminated? Who will draw the line and where will it be drawn? How do we determine suffering? Most people would agree that Downs Syndrome is a medical disorder but anyone with experience with Downs Syndrome individuals will attest to how much happier they often are to the general populace. Thirdly, where do the embryos that research is being carried out on come from? There's an argument to be made from a pro-life point of view but also, there's a financial incentive for IVF treatment labs to fertilize more embryos than necessary to facilitate such research