Prior to a recent debate, I had found the SLED argument fully convincing. The only difference between the born and unborn lives are size, level of development, enviornment, and degree of dependency. These differences exist even between born persons, and do not exclude anyone from personhood. Any reasonable pro-choice person concedes that the unborn are persons at some point before birth. However, they will also point out that the difference in level of development between the born and unborn is far more significant than between any born persons.
From a secular point of view, what makes our lives morally relevant is the way our minds work. It is what distinguishes us from all other animals, and it is argued that until some semblance of that mind exists, there is no person to wrong with death. It is argued that just as the death of the brain is considered the end of a person, even if their body is alive with organs that can be harvested for transplants, the body before the brain shouldn’t be considered a person.
In my last debate, I brought up that the brain begins forming at 3 weeks and they claimed brain activity that can be likened to ours is detected at 24 weeks. I pointed out that as technology improves things are being detected earlier in pregnancy, and convinced them that we risk oppressing people by defining personhood according to the limitations of current technology.
This makes it morally safer to assume personhood at conception, but assumed personhood isn’t really satisying when a later line may be found. At some point during the debate, I stumbled upon the argument of natural capacity. From the moment of conception, a biological human being with unique DNA exists which has a self directed propensity to develop the mind that is valued. I had trouble arguing why that matters, so this is where I need help.
I tried to argue that the mind shouldn’t be isolated from the body to define personhood because it needs the body to express itself. It needs the heart pumping blood to the brain to exist. Even though the body exists before the brain, and starts simple as a single cell, nothing that it is doing is simple. It is splitting and working towards developing everything at once including the brain which holds the mind. This seemed unconvincing, and I’m not able to think of a stronger secular defense for why the body before the mind should be regarded as a person