According to the devout Christian polymath G. W. Leibniz, a complete being, i.e., a genuinely individual substance, is a thing whose nature is given by a notion so complete as to contain in itself all predicates true of the subject to which it is attributed. This is perhaps Leibniz’s most sensational philosophical thesis (and he had many), and is what commits him to say that every person, consequently, has a notion the knowledge of which would allow any knower to deduce from it a priori all the facts that are true of the individual, including facts about him in the future, in the same manner that one with the requisite expertise may deduce from the notion of a circle all of its properties. From the face of it, Leibniz is committed to a thoroughgoing determinism which, more than compatibilism, razes to the ground any sense in the idea of individual autonomy. Yet Leibniz claims that
(J) Julius Caesar became a perpetual dictator.
is only a certain truth (section 13, Discourse on Metaphysics). It is not, however, a necessary truth. But why not?
Consider how truths about the past are known. We know (J), for instance, from historical evidence, eyewitness testimony, written accounts etc., the collection of which tells us the reasons why (J) is true. However, we don’t feel compelled to say that this statement states a necessary truth just because we know its reasons for being true. In the same vein, God, being omniscient, knows all future truths now, since he alone knows all the reasons for the universe’s coming to be, in virtue of which future truths are true. Thus, that God (you may substitute for your preferred deity) knows
(J’) Julius Caesar will become a perpetual dictator.
is true no more means that such truths are necessary than that statements about the past are necessary. This represents an attempt by Leibniz to “pump” our intuitions, to prime us for his attempt at making plausible the non-necessity of future contingents which are known to God—statements about the future which already have determinate truth-values—and which are contained within every individual substance’s complete notion from the time of his or her creation. Let’s see if he succeeds.
To begin, Leibniz distinguishes between certain and necessary truths. (J) expresses a truth that is certain, whose certainty stems from the fact that its obtaining is contingent on God’s choice to actualize the state of affairs that it presupposes (namely, creation of the best possible world). It is not a necessary truth because its opposite, the statement that Caesar didn’t become a perpetual dictator, does not express a contradiction. It would be false should someone utter it, since (J) is true, but its falsity, Leibniz argues, is qualitatively distinct from the falsity of, say, “A triangle does not have three sides.” We might think however that if (J) is true because it is “encoded” pre-determinedly into the notion of its subject, Julius Caesar, then perhaps the intuition guiding us here is erroneous, and that Leibniz is illicitly appealing to ordinary experience as if it was an adequate witness of underlying, metaphysical truths. We might think that such truths are not after all distinct from those truths that we think ordinarily to be per se necessary truths. How would Leibniz forestall this response of simply abrogating this distinction, collapsing all truths into a single class of necessary truths?
Let us begin with what he has to say about genuine or per se necessary truths. Necessary truths, Leibniz informs us, are those whose contraries imply contradictions. That is, such truths whose truth do not depend on God’s actualizing them, and thus could not fail to exist in a less perfect world (our world being the most perfect, or best possible, world). Their corresponding notions are such that the predicates true of them are inseparable from them, and this because their essences are governed not by the principle of contingency or the best, but by the principle of non-contradiction. In this respect, it is clear that such truths are timeless, eternal, invariable, and at least for some of them, fathomable only by way of intuitive apprehension alone (e.g., the law of non-contradiction itself). Thus, just as in the Aristotelian metaphysic essences cannot be demonstrated, and hence have no reasons for their being the case, necessary truths for Leibniz are not demonstrable. Indeed, they constitute the basis for God’s actions and are at the bottom of all other derivative truths.
On the other hand, certain truths, i.e., ex hypothesi necessary truths, are true only on account of God’s creative act, in virtue of which their notions, and all the predicates that are contained within them, do not exist as mere unactualized possibilities. Thus, that Julius Caesar became a dictator is not a necessary truth, since the truth of Caesar’s being a dictator is a fact about his essence that does not entail its existence. Accordingly, the negation of (J) is not a contradiction as that of “Triangles have three sides” is. Notice, though, that Leibniz, in introducing this distinction, construes the non-contradictoriness of ~(J) as issuing from reasons dramatically different than what we would expect, viz., because it’s clear to us that it need not be written into Julius Caesar’s essence for all time that he must become a dictator. Rather, Leibniz sees (J) as not being per se necessary merely because Caesar could have notexisted, if God had willed a less perfect world. I note a different way of interpreting this aspect of Leibniz’s view in my closing remarks, and suggest that both clash with Leibniz’s insistence that the practice of passing moral judgments is as unimpeachable as ever, despite this result.
Once we connect the fact that everything that exists does so because God willed it, and further, that all existents exist subject to the principle of the best, with Leibniz’s idea of complete individual substances as being those things whose natures are given by notions so complete as to contain in themselves all predicates true of the subjects to which they are attributed, it is clear that Leibniz’s sense of non-necessity is unsatisfyingly weak. Take Adolf Hitler, for instance. If Hitler exists only because God saw his existence to be necessitated by reasons pertinent to his goal of creating only what is the best, then the set of all of Hitler’s attributes, before his essence is instantiated, must be wholly unique to him. Otherwise, there could be another possible person, say, Shitler, all of whose predicates contained in his notion are the same as those contained in the notion of the very Hitler we Earthlings are familiar with. The existentialization of Hitler, then, instead of Shitler, would violate Leibniz’s own principle of sufficient reason, since there is no difference, ex hypothesi, between Hitler and Shitler.
Consider the implications of being committed to these claims all at once, as Leibniz is, along with being committed to either a descriptivist or Millian view on names, in particular, proper names.
(a) On a (naïve) descriptivist reading, the statement that Hitler did not massacre scores of innocent Jews would be tantamount to, on Leibniz’s principle of individuation (an application of the principle of sufficient reason to individual substances), a statement that is false not because Hitler did murder scores of innocent Jews; it would be false because it involves a presupposition failure. “Hitler,” when used in this manner, might reference some other person in virtue of the predicate incorrectly attributed to its subject. Plausibly, such a person does not exist, since in our world, there is one man who wrote Mein Kampf, who killed himself in a bomb shelter with his wife, who styled his moustache a certain way, …, and who massacred scores of innocent Jews during World War II. The person corresponding to this description minus the predicate “killed scores of innocent Jews in World War II, is likely to be unsatisfied (and if it isn’t, simply add in more descriptions until it is, and this will suffice for my objection to go through).
This shows, however, that if we say, as a manner of speaking, that Hitler could have not killed innocent scores of Jews, what we really mean, on the naïve descriptivist reading, is that someone else did not. So the sense of non-necessity attributed to Caesar in (J) would be the same sense in which Hitler was not necessarily a killer of scores of innocent Jews. This is clearly a hopeless conceit, if the intent is to secure a robust sense of freedom good for Leibniz’s exhortations that we should not be “quietists” in the face of knowing that all of our predicates were implanted in our notions at birth.
(b) On the Millian view, which is the view I think most congenial to Leibniz’s view, as we shall see, the problem is what has been gestured toward in my remarks on the basis of Leibniz’s distinction between certain and necessary truths. Once again, consider what it would mean for (J) to be false on this view of names. On the Millian theory of proper names, a name designates its referent essentially, i.e., without regard for the “accidental” properties—e.g., being blue-eyed, being heirs to a multi-million dollar clothing company, being the person who betrayed Jesus, etc.—in virtue of which we distinguish between different individuals. Kind- and proper name-fixing occurs, rather, naturally upon appropriate introduction of the essence into a community’s sociolinguistic vocabulary or practice through “contact” with its associated subject. Thus, when we speak about Aristotle, we mean to refer to that man whose essence is uniquely signified by the use of “Aristotle” according to the features of this context. (So, whether we’re speaking of Aristotle, the Greek philosopher student of Plato or Onassis, the 20th century shipping magnate, is determined by the features of the context of our conversation.)
Because Leibniz’s view of notions is functionally the same as his view of an individual’s nature, i.e., an individual’s essence, if annexed to a Millian view on names, ordinary proper names would invoke the entire set of a subject’s predicates, in much the same way as they would be on the naive descriptivist view. The relevant difference is that on this Leibniz/Mill hybrid, the falsity of a statement that is true of some contingent being implies that being’s nonexistence, whereas on the Leibniz-descriptivist hybrid, that is not a necessary implication. Reference failure is possible without implying the intended referent’s nonexistence. So on this view, what makes Hitler’s actions in World War II unnecessitated is simply that he could have not existed. And this is just what Leibniz thinks goes on when we talk about possibility with respect to an individual’s predetermined predicates.
This brings me to some final thoughts on these final issues I’ve raised. What are the moral implications for either (a) or (b) above for Leibniz and his devotees? It may be said that (b) might be able to preserve a modicum of sensible talk, however affected, about moral responsibility, but it is clear it would do so only by combing over acknowledged infelicities that, under full awareness, is destructive of the illusions descried. For instance, if in acting a certain way, one knows that his choice is between doing so or not existing, it is not clear to what extent that person may be faulted for choosing the former. Further, one does not actually have a choice in the latter, since, on Leibniz’s story, his existence was necessary, and somehow figured in his vision of the best possible world – the world in which, say, Charles Ponzi is a recidivist conman and unable to appreciate the moral insights of Jesus or Aristotle – the actual one. This view may however be rescued by a semantics that treats the relevant conditions for invoking counterfactuals as being dependent on what it would take for a person not to exist, but the prospects of getting this contrivance to square with our intuitions aren’t great.
On (a), a similarly peculiar implication is observed. If the nature of a person just is the collection of predicates contained in his notion, then given the principle of sufficient reason, the person is picked out by the same attributes in all possible worlds. This follows from the fact that our world, because the best, is the only world in which his notion corresponds to an actual person – himself. In all other worlds, talk about him from that world is meaningless. In other words, counterfactual talk about the alternative ends Charles Ponzi could have assumed instead of grifting inveterately rely illegitimately on ascribing to him the properties that, properly speaking, belong to another possible person. If this is so, statements concerning possibility apply, at best, to an individual’s “counterpart.” So, for example, when someone is thrown behind bars for hitting and running on the rationale that he had the choice not to do so, what would be meant, instead, is that his counterpart, descriptively similar in almost all respects except for the fact that he did not run away from the scene of the incident, did not do so. But this clearly would not be what we mean–certainly not what a judge in a court of law or a jury has in mind–when we censure or laud others for their misadventures or good deeds.
This difficulty of the view may be treated by applying John Searle’s idea of a “sufficient but vague and unspecified number” view on the content of descriptions which are associated with proper names. This is his idea that an individual merely needs to satisfy a sufficient subset of the disjunction of non-necessary predicates associated with his notion for him to be its referent. Searle doesn’t state exactly what constitutes having a sufficient quantity of the properties, but presumably, the referent must have more than half of the descriptions associated with the name in any world in which its nature is instantiated, to avoid there being another individual in the same world who can fulfill to the requisite degree the description associated with his or her name. Searle also says that certain properties should probably be weighed more heavily, like the famous deeds of the person being spoken about. It remains to be seen how much mileage we can actually get out of this view, as it seems, prima facie, to be merely a Millian view in disguise. When studied against the spectre cast by Leibniz’s strictures on the nature of a substance’s notion, it is clear that the only non-necessarily instantiated properties are those that make the notion belong to a different person, i.e., those the substitution of which into an instantiated notion render its possessor’s existence an impossibility. Served in this guise, the consequences that we saw on (b) creep into view for (a).
For my part, neither the non-necessity in (a) nor that of (b), it seems, is underwritten by the conditions that we would expect are necessary for moral judgments to be applicable in the sense in which they are typically passed in ordinary conversation. So, even though the preceding has not been a wholesale refutation or admonishment of caution for all possible interpretations of Leibniz’s views on autonomy and contingency, I have no major scruples with suggesting that I have at least cast doubt on Leibniz’s ability to reconcile his moral realism with the interpretation we have considered in this article.
 Leibniz’s Principle of the Best is the principle that God not only does everything for a reason, but further, that any reasons are always constrained by his solicitude for bringing about what is, all things considered, most good. Use of this principle with respect to contingent beings must, of course, be reconciled with the laws of nature whose reality God’s creation of our world is consequent upon, and which he thus brings to bear, since these provide the non-miraculous, ordinary influences that will set our world in motion, as it were, and to which all physical beings are contingent.
 I.e., conceivability is not what Leibniz is invoking in order to establish that the contrary of, say, the true statement “Caesar became a dictator” doesn’t imply a contradiction. If that were so, he wouldn’t have worried about those who argue that if the notions of substances are determined such that they contain all of their subjects’ predicates, we are in fact not free, whatever we conceive. The rationale behind Leibniz’s test of contradiction is, rather, that while there are reasons why predicates belong to their subjects, necessary truths are true without there being reasons for their truth. So, a proof of all the predicates of a subject’s notion only shows that there are reasons for each predicate’s being true, not that they are necessarily true. On the other hand, necessary truths don’t have reasons, even if they can be demonstrated (i.e., their truth cannot be explained, and is independent of God).
 Leibniz maintains that, e.g., Alexander the Great’s complete notion is the result of his essence, or nature, which is the ground of all of the predicates contained in his notion virtually (those that are true of him in the future or are true of him in the past) or explicitly (those that are true of him at present). He also maintains that the soul is the subject of its properties, therefore suggesting that souls are not simply the totality of their properties, but rather, grounds of their properties (and so in theory separable), unlike complete notions. Thus, this allows Leibniz to reject the objection that fromhis thesis that from notions of individuals all their predicates may be deduced by an able being (God, i.e.) the parallel claim that from an individual’s essence or soul all properties of its bearer are deducible from it, i.e., contained in it, follows. Rather, the essence presupposes in addition the reasons for the notion of the individual containing the predicates that it does (see section 13, Discourse on Metaphysics), which are of course, constituted by God’s free choice to create that individual. The reduction from notion to essence, existence of an essence to God’s free act to instantiate it, follows straightforwardly.
 Not in the Lewisian sense, obviously, since these would be conceded at the outset to be distinct from the relevant subject of moral evaluation (though this in my view is a wholly semantic difference).