The following is the second argument adduced for the univocity of the concept of existence in the Bidayat al-Hikmah. Allameh writes:
Another proof of it is that after positing the existence of something, at times we have doubts about its essential characteristics. For instance, after affirming the existence of a creator for the world, we may have doubts as to whether the creator is a necessary (wajib) or a contingent (mumkin) being, or as to whether or not [He] is characterized with quiddity (mahiyyah). Or, for instance, after affirming that man has a soul (nafs), we may have doubts as to whether it is material (maddi) or immaterial (mujarrad), a substance (jawhar) or an accident (‘aradh). Hence, if ‘existence’ were not univocal in the different instances and were it an equivocal or homonymous term with disparate meanings (mushtarak lafzi), its meaning would necessarily vary from one subject of which it is predicated to another.
I take the gist of this argument to amount to the idea that the fact that we are able to affirm the existence of certain things but still entertain doubts about some (other) features of them goes to show, for Allameh, that existence must be univocally predicated of the things of which we affirm it. For otherwise, if it was equivocal, we wouldn’t be able to do that. That is to say, the meaning of existence, each time we affirm it of things (but have doubts about other features of them) would differ significantly to such an extent that we wouldn’t be able to know what we mean when make statements such as “x exists and y exists but whether or not x has property a or y has property b is unknown.” But we do know what such statements mean, so ‘existence’ must be a univocal concept. In other words, the different instances in which we use the concept of existence all go to show that it is univocal. If it wasn’t, we wouldn’t be able to use it in the way in which Allameh specifies that we in fact do.
This second argument, or more specifically the fact that we are able to use the concept of existence meaningfully in the contexts which Allameh lists, suffers from the same problem as the first; namely, although it rules out ‘existence’ being equivocal, it does not it seems to me rule out the possibility that the concept may be analogical instead. On the contrary, it seems to me that the term existence can be analogical used (in the way Allameh’s argument requires) in various propositions without impugning the intelligibility of these propositions. That is, given that one can intelligibly and meaningfully analogically predicate existence of (a) different things and also (b) have doubts about certain other features of those things, then meeting conditions (a) and (b) does not require – contrary to Allameh’s claim – that ‘existence’ be univocally predicated. Hence, the univocity of existence would then not be necessary to fulfill conditions (a) and (b).
Here are some examples to illustrate the point. Take the following two statements:
(1) “An animal is healthy and food is healthy but whether the animal is x or the food is y is unknown.” This statement is perfectly meaningful, even though the term ‘healthy’ here is analogical not univocal.
(2) “God exists and the soul exists” or “a substance exists and an accident exists but whether or not … etc.” These statements are also perfectly meaningful and understandable even if we suppose the term ‘exists’ to be predicated analogically of the subjects of the statements.
What the above considerations show is that the unintelligibility which equivocality would engender in the contexts which Allameh lists if the concept of existence were an equivocal term would be absent from ‘existence’ in such contexts if we suppose it to be an analogical term. Given that, Allameh’s second argument then, like his first, does not seem to me to necessarily rule out existence being analogical or, the same point put differently, require necessarily that existence be univocal.