There are still many forms of slavery in the world, and though it is taking hundreds of years, one by one, slavery in all its forms is being eradicated. Males used to be the slave of choice for their strength as labourers and soldiers, but men are largely now so enfranchised that there are few male slaves. (Men were always first to win privileges such as education, votes, wages, equality under the law, protection from the state, the right to combine, etc, in part because they were able to use their physical strength to win these freedoms for their sex. As infuriating as this is to the recipients of largess that is only their due, it is fact that it was only when enough decent men understood that women were deserving of the same rights, was the physically "weaker sex" granted equal rights by the more powerful "stronger" sex.)

Children and women are now the human slaves of choice, many as sex-slaves, an old-fashioned term that, sadly, still applies. As well as being sex-slaves, children are also being used as war-fodder slaves. The strong are able to raise their own status, but the weaker have to depend on the strong to raise their status to equals under the law. At least one war was fought, in part, to free male slaves, and wars, in various forms and in various venues, are -- right now -- being fought to free women and children from the bondage of both labour- and sex-servitude.

Labour- and sex-servitude exists for the pleasure of the strong: unpaid labour produces pleasurable wealth for the enslaver; sexual servitude provides a pleasure that requires no elaboration; indeed, elaboration degrades the elaborator.

Which brings me to animals. Animal servitude exists for two purposes, both of which create pleasure for humans: acquiring money or companionship.

Generating money is by far the largest purpose of animal-slavery. Food (the largest), research, entertainment, "art", competitive events (such as horse-racing and dog-fighting), clothing, the companion-animal breeding market, and much of the "animal-welfare" industry, produce trillions of dollars in wealth a year.

Since animals are the weakest sentient beings of all -- weaker than women and children -- animals will only be granted equality as free beings when enough free humans decide to award it to them, as happened for black slaves in the past. The idea of animal rights has existed for thousands of years, but now the idea of the right to liberation from bondage to humans; the understanding that animals are not ours to own, use, or derive pleasure from, is gaining credence at the warp-speed of internet technology.

It may be the final freedom of sentient beings from the tyranny of the strong, but it is clearly coming.