Infanticide or killing recently born children is considered a crime because such an entity is regarded as a human being.
Abortion, however is not considered a crime because a fetus is not regarded as a human being.
What is a human being? Quite obviously the psychological sense of self or the capacity for an intellectual conception of the world is the essence of man. An infant does not have a mind of a human. He is in closer affinity with most animals than humans for this reason.
Because an infant is not a human, he ought not to be granted the right to life and is therefore the property of the state or his biological parents. It is up to one of the two to decide whether the infant should live or die.
The fact that he has potential to become a human being is irrelevant because law by definition deals with entities that are and not entities that could be.
A normal child may be dispensed with until he has reached the age of 2, or clear-cut psychological functioning. A child afflicted with mental retardation may be killed until he has reached the age of 5.
Thus in summary, one should not be awarded the basic human rights until one becomes human or acquires a psychological sense of self, until then he is to be regarded as property of those who do have such a sense of self.
I've been pondering about this too recently. Babies and Children have been dispensed out of necessity (the parents needed to get rid of it to survive, they couldn't keep it alive without endangering their own lives) for centuries without it being a crime but now for some reason we think we are above it. People now see that as brutal and immoral, but to those same people it is okay to kill someone because that person happened to murder someone else. Logical survival methods are deemed 'Bad', whilst illogical revenge instincts are rendered 'Good' (I shouldn't have to explain why revenging a death is illogical and worse than killing an infant.) However it should be noted that an unwanted child should primarily be set up for adoption over just killing it lol. And if it can't get adopted in a timely manner for some reason, then it should be killed in a humane manner.
What really is the difference between an embryo/fetus compared to a baby that has been birthed? The baby is outside of the mother, woopty-doo. It is still equally dependent the mother, its brain is barely developed and its skull will have to harden with time, it cannot consciously control its movement, it has no discernable thought other than primal insticts (food, poop) and its attempts to express these needs can barely be distinguished from one another, it has no traits to distinguish it as an individual other than genetic phenotype and will continue being a bland organism until personality starts developing in toddlerhood.
The only part I disagree with you on is the ages.
If a child reaches the age of two it should be given up to an orphanage. Before then if the parents wish to get rid of it, an adoption agency is prefered, but if they want to go as far as 'putting it to sleep' in a humane fashion than that is their decision as the owners of the child.
Retarded babies.. difficult. This is where there is a huge F-T divide so I don't want to say anything that gets me castrated.. What I'll say is that I disagree with age 5 for the time-span where it can be legally murdered, it should be up to age 2, same as a normal child, but it should be able to be dispensed of to an orphanage up to age 8.