I am a slave so my answer is in danger of bias. However, One must define slavery and define man, enumerate all the possible areas of slavery, in order to start to understand the answer. There are seven basic forms of slavery-just as there are seven lights on a Menorah, or seven spirts of man. But what it all boils down to, since slavery is just another form of murder, and tossing in the fact of Reciprocity that language cannot exist without, what a simple minded question.
One must look at the question in its most general form, why may one word be or not be predicated of another? Why can I place one member in a class or not? Study Plato, Language, Study in Lucid dreaming.
What is predication? Is man yet literate enough to understand he is yet pre-literate?
At any rate, if you knew what good and evil were, what right and wrong were, then it would the definition of those that determined class membership--this is elementary math--there are two and only two methods of constructing a set, enumation and definition.
Since predication is the inverse function of abstraction, one must "know themselves" in order to start to comprehend the fundamentals of grammar, thus logic and judgment.
When one knows the foundation of judgment, one does not ask another man, or even a god, as to what is right or wrong, one asks the standard, the definition. Thus, if man knew the principles of judgment, one might see how radically different society, and human psychology must become in order for truth and understanding to exist on this earth. j.c.
P.S. What is a definition? How does it differ from a description? How many primitive categories of words are there? Which can be defined, and which not? Why? One should really study Plato and Euclid.