The debate really centers around what humanity is. It is not wrong to kill a bird, a deer, a spider, or a dog because animals lack humanity. However, humans who fail to meet the criteria for having humanity are no different than dogs, spiders, deer, and birds. It is not wrong to kill a gamete, zygote, embryo, fetus, or human in a total vegetative state. I don't care how "cute" you think it is. All things that are new experiences to us are awe-inspiring: seeing a picture of an embryo for the first time is no exception. I of course refer to those who gawk at video boards and billboards depicting fetuses and embryos while saying that it is wrong to kill it because it has individual toes.
Humans are animals. Hence the fact that we are in the Animal Kingdom. We are not some special being above animals. However, we do have our ability to think rationally, logically, and reasonably; we have the ability to sustain our own lives even without the help of society (e.g., we can eat, drink, and breathe on our own); in addition to the aforementioned rational thinking, such thinking that we possess is conscious thought (that is, we can metathink, or think about thinking); we communicate in an effective and intelligent manner; and we have emotion.
While other animals may have some of those qualities, no animal has them all, and certainly none of them are of the species Homo sapiens.
I have just named the five qualities and one requirement of humanity. To put them simply:
- Of species Homo sapiens
- Ability to reason logically
- Ability to sustain own life (homeostasis)
- Ability to meta-think
- Ability to communicate effectively and intelligently
- Ability to have emotion
- To have humanity, only the requirement and ONE of the five qualities are needed.
Fetuses (and those in prior stages) do not have humanity because they do not have EVEN ONE of the Five Qualities.
Fetuses cannot reason logically. In fact, psychologists have determined that mature logical reasoning onsets around the age of seven years.
Fetuses cannot sustain their own lives. Rip a fetus out of a mother two months early and it will die without life support (and probably even WITH it). Now what if it is two-weeks early? A two-week premature birth, while the human is still a fetus, it can be determined to be an infant upon examination. If it can breathe on its own and its brain functions normally on its own, it passes the homeostasis test, and thus into a state of humanity. (Note: this is not the ability to BE sustained, but to sustain one's own self unaided.)
It has not been psychologically determined that fetuses have conscious thought. Therefore, we should assume that it does not have conscious thought until we can see through its actions that it has conscious thought. The default value for consciousness is 0. The default for anything is null. One must prove that there is something, not that there isn't something. The burden of proof lies on the person who says that something is in fact there, not on the person who is using current knowledge (that there is nothing). This argument can be applied to a number of things, from the teacher whose students didn't do their homework to debates about the existence of gods.
Fetuses cannot communicate effectively and intelligently. If a fetus comes up with some sort of mutual communication with its mother that can be exhibited as proof, call me.
Finally, it has not been determined that fetuses can have emotion. This follows the same argument as that for conscious thought. Physical pain is NOT an emotion (it is an instinctive response to a dangerous physical stimulus), and as I have discussed, it cannot have emotional pain, for what conscious thought enables emotion? Emotion is the capacity to have it coupled with conscious thought in order for the brain to process it.
In similar light, humans in the vegetative state lack humanity.
In final summation, the following things do not have humanity:
- dead humans
- humans in a total vegetative state
- sperm, follicles, gametes, zygotes, embryos, fetuses