From BBC Ethics Guide
What is speciesism?
'Speciesism' is the idea that being human is a good enough reason for human animals to have greater moral rights than non-human animals.
Speciesism and bigotry
Speciesism is often condemned as the same sort of bigotry as racism or sexism.
People who oppose speciesism say that giving human beings greater rights than non-human animals is as arbitrary (and as morally wrong) as giving white people greater rights than non-white people.
NB: Those working for racial or sexual equality often find this comparison insulting - they say that their struggle for equality has a moral and social importance that animal rights can never have.
Speciesism is common
Most people, faced with a difficult choice between a human and an animal, would probably react in a speciesist (or 'homocentric') way.
Consider this example:
A child and a dog are trapped in a fire. You can only save one of them. Which will you save?
- Most people don't have to think about this for even one second.
- Most people don't consider the relative moral status of the dog and the child relevant to their choice.
- Society would condemn anyone who delayed in order to consider the correct moral choice.
Pure speciesism carries the idea of human superiority to the extreme of saying that the most trivial human wish is more important that the vital needs of other species... for example a pure speciesist would argue that it's ok for animals to be cruelly treated and killed to provide fur decorations for human beings to wear.
Few people take speciesism to this length. More commonly, they say that all other things being more or less equal, it's morally correct to take the human side when considering an ethical issue.
Species is not a moral factor
People who object to speciesism say that a difference of species is not a morally relevant difference - in the same way that a difference of race is not a morally relevant difference between human beings.
They say that speciesism amounts to treating morally similar individuals in morally different ways for an irrelevant reason.
Supporters of speciesism say that there is a clear difference between humans and other species, and that this difference affects their moral status.
They argue that human beings are more self-aware, and more able to choose their own course of action than other animals. This, they say, enables them to think and act morally, and so entitles them to a higher moral status.
But the argument that there are morally relevant differences between human animals and non-human animals is not a speciesist argument, since the argument is about the particular characteristics that are being put forward to justify the different moral status of human and non-human animals.
Speciesism as 'natural'
One argument in favour of speciesism is that it is biologically natural to treat one's own species favourably. Virtually all non-human animals treat members of their own species better than those of other species.