Which is why, in the case of issues which produce a wide-range of values, ethics and opinions, we often consider it prudent to permit each individual to make their own assessment, rather than imposing a 'one size fits all' draconian law!
Are not all of our laws based on an absolute? For example, do this and this happens. Don't do this and something happens. If not there would not be laws but suggestions. Yes, there are different degrees of murder in our laws, however each is determined on a degree of pre-meditation or culpability. Yet there is no sliding scale of individual assessment, especially with the 'actor' of the action.
Yet, with regards to abortion in taking all values, ethics and opinions (which are subjective particulars) into account for abortion we ignore an absolute. The established science that someone of our being of the class of human is determined at conception. Taking the various values, ethics and opinions, as you mentioned, would it not be more enlightened of a modern scientific minded society to go with what we
know and not take a
'guess' leaning on the various opinions?
Would not the logical approach be as the Aikido who say 'do no harm?' Meaning if we are not sure we take no action.
This would have to be a logical and ethical conclusion even for a non-religious secular adult human being. If we allow human life (which you do not deny at the very least is present at conception) to be defined by whim or popular opinion, don't we devalue human life to the point where other areas of human development outside the womb becomes debatable?
We have had too many of those definitions in our history (and today as well) of people, groups of people, governments, religions, despots defining what is human, not human or sub-human.
Using the model of 'wide-range of values, ethics and opinions' is a poor model because it has led to genocide, slavery and oppression.
For example, based on your model of ranging values, ethics and opinions we have such an opinion from Peter Singer:
"We can plausibly argue that we ought not to kill, against their will, self-aware beings who want to continue to live. We can see this as a violation of their autonomy, or a thwarting of their preferences. But why should a being’s potential to become rationally self-aware make it wrong to end its life before it has the capacity for rationality or self-awareness?
We have no obligation to allow every being with the potential to become a rational being to realise that potential. If it comes to a clash between the supposed interests of potentially rational but not yet conscious beings and the vital interests of actually rational women, we should give preference to the women every time."
(http://www.scotsman.com/news/analys...for-the-sake-of-the-unborn-1-2467196)---Peter Singer in Why it’s irrational to risk women’s lives for the sake of the unborn
If the above is not fraught and packed with the dangerous 19th and 20th century eugenics philosophers here's more from 21st Century Peter Singer:
"If life with quadriplegia is as good as life without it, there is no health benefit to be gained by curing it. That implication, no doubt, would have been vigorously rejected by someone like Christopher Reeve, who, after being paralyzed in an accident, campaigned for more research into ways of overcoming spinal-cord injuries. Disability advocates, it seems, are forced to choose between insisting that extending their lives is just as important as extending the lives of people without disabilities, and seeking public support for research into a cure for their condition. ("http://www.nytimes.com/2009/07/19/magazine/19healthcare-t.html?_r=0)
Here he compares the worth of animals to human born babies:
Infants are sentient beings who are neither rational nor self- conscious. So if we turn to consider the infants in themselves, independently of the attitudes of their parents, since their species is not relevant to their moral status, the principles that govern the wrongness of killing non-human animals who are sentient but not rational or self-conscious must apply here too. As we saw, the most plausible arguments for attributing a right to life to a being apply only if there is some awareness of oneself as a being existing over time, or as a continuing mental self. Nor can respect for autonomy apply where there is no capacity for autonomy. (Taking Life: Humans Peter Singer Excerpted from Practical Ethics, 2nd edition, Cambridge, 1993, pp. 175-217) (http://www.utilitarian.net/singer/by/1993----.htm)
