We are told in the Sources that servorum una est condicio. This proposition expresses, in an inaccurate way, a fact;i.e that in general all slaves are in the same position, in that their faculties are derivative. The slave, as such, has scarcely anything that can be called a right, and the liabilities of most slaves are much alike. But whatever Justinian and his authorities may mean, there is no evident sense of the phrase in which it is exact. In social standing there is the widest difference between different slaves. In legal capacity they differ, if not so widely, at least considerably. These differences are however for the most part not due to any peculiarities in the slave, but result from something affecting the holder, or his title, or from something in the authorisation conferred on the slave. A slave with peculium is the same kind of slave as one without. So in the case of a derelict slave, or one pendente usufructu manumissus. But there are some cases which cannot be so explained away. Such are that of the statuliber who has a sort of incapacity to be jurally injured, though he is still a slave, and those of servi publid populi Romani,servi fiscales, and, possibly, servi municipii, who have privileges not distinguishable from property rights.

Real or apparent, inherent or resulting from their special relations with other persons, these distinctions need discussion: accordingly we shall consider the special cases in which the position of the slave causes exceptional results to flow from his acts, or from acts affecting him. As the cases are for the most part quite distinct, no attempt is made at anything more than rough grouping.