 Fârâbî’s distinction between being-as-true and being-as-having-a-quiddity-outside-the-mind also allows him to resolve the issue about whether being is univocal or whether it is said of one thing (or of one kind of thing) primarily and of other things in a dependent and derivative sense. Looking only at one-place cases, being-as-true must be univocal to beings in all categories, and also to beings in no category such as negations or privations and beings per accidens like white horse. For I must be able to ask “is the concept of X instantiated?” before I know what category the instances of X will fall under, or even whether X will turn out to be merely a privation, or an accidental combination of two positive entities. (If X is eclipse, we might reasonably start by keeping many of these options open: only the investigation of actual eclipses, if it turns out that there are some, will determine which option is right.) By contrast, “what has a quiddity outside the soul, although [being in this sense] is general, is said by priority and posteriority in order” (I,92 p.118,14–16), since if the quiddity of X involves a reference to Y as the cause of existence to X, then Y has a prior and stronger claim than X to have a quiddity outside the soul, rendering it capable of independent existence. First, substances will be prior in this way to accidents, since for an accident to be is for it to belong to a substance, and the scientific definition of any kind of accident will mention the kind of substance that it can be predicated of. But then, within the category of substance, “what requires a differentia or genus in this category in order for its quiddity to be realized is more deficient with respect to quiddity than the thing in this category which is a cause of the realization of its quiddity”, and by pursuing causes of quiddities in this way we can come to some first substance, “whether this is one or more than one”, which has a stronger claim to the title of “being” than all other substances, and a fortiori than accidents (I,92 pp.118,18–119,4).