"Rights come from society" (or "Rights are granted by the state").
Rights are not tokens handed out by countries. You always have rights. The state has no more authority to hand out rights than a clown at the circus. — Hugh DiedrichsThat's a great quote, but by itself it's only a counter-assertion, so let us continue to the argument. The claim is that rights come (or are granted by) either "society" or "the state". First, let's understand that the two assertions are the same: in a democracy the state is controlled by majoritan tyranny (see The State is Us), and in other types of state, presumably the "society" version of the assertion would not be made. We can consider the case that it is meant that society actually means everyone, but that does not hold up to scrutiny: if I withdraw my consent for someone to be free, they do not become bound.
The fallacy implies that rights may either be withdrawn or not granted, leading to a reductio ad absurdum wherein it is implied that since the state promoted and supported slavery at various times and places in history, at those times the right to liberty was not granted to those slaves. That is, they had no right to liberty unless and until it was granted. A right is a legitimate claim on something (not the power to do something; right and power are often confused; see Might Makes Right). When it is correctly understood that rights are innate (see Natural Law), one can distinguish between a right to be free, which always exists, and the power to exercise that right, which does not always exist, as in the case of a slave. The right is infringed but not taken away.
Under the "rights from the state" theory, even if a slave has the opportunity to escape, or is freed by another person, they still do not have the right to be free unless the state decides to grant it; it is thus a moral wrong for them to escape their master.
It is not enough for some that their theory declares slavery right if majorities want it, however (sad though that is). But more fundamentally, an individual's claim to control their own body (self-ownership), and hence their production, liberty, and legitimately acquired property exists outside of the approval of others. Others may be able to restrict the ability of a person to exercise the right; but the legitimacy of the claim exists outside of approval or violent infringement.
Power is not right; one may have the power to harm someone, but not the right, or the right to harm someone, even (e.g., in self-defense), but not the power; or both or neither; they exist independently.