@Pepshort
“Your definition of sentience is applicable to all mammals. ”
Yes, it is. And I believe that all mammals have some basic rights, such as the right not to bve treated as the means to an end and the right not to be killed unless it is necessary to avert a greater harm.
“What distinguishes human beings, then, from other mammals?”
It depends on what we are talking about. I explained here about my feelings on pain and death regarding humans versus other animals.
There is no hard line separating us and other animals.
As far as souls go, I stand by what I said. We cannot base anything on whether or not someone or something has a soul as we cannot see it, cannot define it, cannot test it, cannot prove it. We can only take someone’s word for it- and how do we have any way of knowing, them, who is right- the Christian who believes that only humans have souls or the pantheist who believes that everything does?
As far as “the statement found in the U.S. Constitution that ‘all men are created equal”- it’s a rhetorical statement that the founders didn’t really believe themselves. Black men were not equals, women where not equals, and so on.
From a rights-based perspective, all humans are equal because all who have inherent value have it equally. As Tom Regan wrote -“Suppose we consider that you and I, for example, do have value as individuals — what we’ll call inherent value. To say we have such value is to say that we are something more than, something different from, mere receptacles. Moreover, to ensure that we do not pave the way for such injustices as slavery or sexual discrimination, we must believe that all who have inherent value have it equally, regardless of their sex, race, religion, birthplace and so on. Similarly to be discarded as irrelevant are one’s talents or skills, intelligence and wealth, personality or pathology, whether one is loved and admired or despised and loathed. The genius and the retarded child, the prince and the pauper, the brain surgeon and the fruit vendor, Mother Teresa and the most unscrupulous used-car salesman — all have inherent value, all possess it equally, and all have an equal right to be treated with respect, to be treated in ways that do not reduce them to the status of things, as if they existed as resources for others. My value as an individual is independent of my usefulness to you. Yours is not dependent on your usefulness to me. For either of us to treat the other in ways that fail to show respect for the other’s independent value is to act immorally, to violate the individual’s rights.”