Any good policy will be good for the one and good for the many.
Do you agree?
http://www.youtube.com/watch?v=Xa6c3OTr6yA
You say that all are equal.
A hypothetical might shed light on whether that is true or not in terms of survival, which I class as a moral principle.
If for some reason there could only be one human chosen to repopulate the world after some imaginary disaster, are all equal to the task?
No. Only a pregnant woman would be able to reboot the species. Of course, the child in the womb would need to be a male. This indicates that to serve the needs of the one, who wants to become many, a pregnant female is the best choice.
If not pregnant.
If there was only two people to be chosen to be saved, then either a productive man and woman or a woman and male child would be the best choice. In terms of duty to protect, the man would have to take the lead in protecting the female, be she pregnant or not, as she must live if the species is to have the best chance to grow.
Not to get gory here but a woman can use a newly dead man and reboot the population alone whereas a man cannot in any way use a dead woman.
If in our scenario 3 or more are chosen to live, the ratio should always favor the female.
Do you still think that all are equal?
If not, then you recognize what is good for the one. It follows then that what is good for the one is good for the many. The ancients knew this and that is likely why they allowed themselves multiple wives. As resources and populations increased, that perceived need or want disappeared. Almost.
Woman's womb and breasts makes her more valuable than a man. This serves man well as he, being more aggressive and sexually demanding than women, generally speaking, is why he instinctively knows that he is to be the protector and bend the knee to woman and elevate her to the top of society.
Regards
DL