History of PHilosoPHy Quarterly Volume 27, Number 3, July 2010 197 Thomas aquinas on The PerPeTual TruTh of essenTial ProPosiTions Gloria Frost i. introduction It is well known that Thomas Aquinas thought that creaturely es-sences did not exist apart from the individual creatures to which they belonged. Aquinas writes in his Commentary on the Sentences that "no nature has being except for in its supposit. Indeed humanity is not able to exist unless in a man."1 It is also well known that Aquinas thought that the truth of a proposition depends on a corresponding being to which it conforms. In the De veritate, for instance, he writes, "To every true act of understanding there must correspond some being."2 While both Aquinas's understanding of essences and his conception of truth have received much scholarly attention, his thought on a certain implication of these two views has yet to be explored. A significant philosophical difficulty arises when one couples the view that essences depend on their subjects for their existence with the view that true propositions depend on a corresponding being for their truth. If essences perish with the substances to which they belong, then it seems that nothing remains to ground the truth of essential propositions about subjects that no longer exist. If the essences of dinosaurs, for example, perish with the dinosaurs themselves, to what being can the proposition dinosaurs are sentient correspond?3 Although Aquinas himself never discussed this difficulty, later Scholastics viewed it as quite a significant problem. The great historian of medieval philosophy Francisco Suárez wrote, "[I]f the essence perishes when the existence of the substance is taken away, then those propositions in which essential attributes are predicated of a thing are not necessary or perpetually true. . . . [A]ll truths about creatures would be contingent and accordingly, a science of creatures would not be possible since science regards only necessary truths."4 198 HISTory oF PHIloSoPHy QuArTerly Suárez refers to this difficulty as "well-worn" since it was such a widely discussed problem during his time.5 Not only did this difficulty capture the attention of the "second Scholastics," but it continued to be a topic of interest to early modern philosophers. Many have claimed that the later medieval discussion of the grounding of essential propositions influenced rené Descartes as he crafted his own controversial view on eternal truths.6 Although Aquinas never explicitly discusses the issue of how essential propositions can remain true after the subjects that they are about perish, his thought contains resources for addressing this problem of both historical importance and philosophical interest. In this paper, I will draw on various aspects of Aquinas's thought to reconstruct his account of how propositions that predicate essential attributes of creatures can remain true after the creatures they are about perish. one result that I will show, which may be surprising to some students of Aquinas's thought, is that his solution to this difficulty does not involve identifying a feature of God as the being to which essential propositions about nonexistent creatures conform. I suspect that many who are familiar with Aquinas's teaching that God has ideas of creatures may think that Aquinas would invoke these necessarily existing ideas of God to ground essential truths about creatures.7 Not only will I show that Aquinas has a different solution to this problem, but I will also explain why he would have rejected the view that God's ideas ground essential propositions about creatures that have perished. ii. aQuinas's Views on tHe GroundinG of Past-tense continGent ProPositions essential propositions about subjects that have perished form a subset of a larger class of true propositions about things that do not now exist but have existed in the past. Accordingly, we can gain some insights into Aquinas's thinking on our topic by analyzing his views on the grounds of another type of proposition in this class, namely, contingent past-tense propositions such as Aquinas was a master at Paris. The nature of the truth of tensed propositions was the subject of great debate in the later Middle Ages. This controversy centered on the relationship between the tense of a proposition and the content that it asserted. Medieval thinkers wondered whether a set of propositions, such as Albert will be Thomas's teacher, Albert is Thomas's teacher, and Albert was Thomas's teacher all asserted the same content, in this case, a certain relation between the subject Albert and the predicate Thomas's teacher, which they called an enuntiabile. one side held that each proposition asserted the same enuntiabile, which is in itself tenseless. According to this view, since each proposition asserts the same content, each proposition has the same truth-value. The other side held that the enuntiabile asserted by the proposition is itself tensed. Accordingly, each of the propositions listed above about Albert's being Thomas's teacher has a different content depending on its tense; thus, it is possible for each to have a different truth-value.8 Aquinas supported this latter position, and a certain objection that he considers to it reveals an important insight into his thinking on the ontological grounds of past-tense truths. Aquinas considers the following objection raised by those who thought that propositions have the same content and truth-value if they differ only according to tense: "[W]here there is the same cause, there is also the same effect. But the same thing is the cause of the truth of these three propositions: Socrates sits, Socrates will sit, and Socrates sat. Therefore, the truth of these is the same. But it is necessary that one of these is true. Therefore, the truth of these propositions remains immutably."9 What is of most interest for our purposes is the objector's claim that the same being causes the truth of both present-tense and past-tense propositions with the same subject and predicate. In Aquinas's reply, he accepts this claim, but he adds an important qualification: To the fourth, it must be said that the sitting of Socrates which is the cause of the truth of this proposition Socrates sits does not have the same status while Socrates sits, after he will have sat, and before he sits. Accordingly, also the truth caused by Socrates' sitting has different statuses and is signified in different ways by present, past, and future tense propositions. Hence, it does not follow that although one of the three propositions [that is, either the present- , past- , or futuretense proposition] is true, that the same truth remains invariably.10 In this text, Aquinas claims that the cause of a past-tense proposition's truth is the same object that caused the corresponding present-tense proposition to be true when it was true. This is to say that Christopher Columbus's act of crossing the Atlantic ocean caused the truth of Columbus is crossing the Atlantic when this present-tense proposition was true in the year 1492, and this same action of Columbus's in 1492 also caused the truth of the past-tense proposition Columbus crossed the Atlantic, which is true today. Aquinas claims, however, that the object that causes both the presentand past-tense propositions' truth has a "different status" when the past-tense proposition about it is true. According to Aquinas, this explains why presentand past-tense propositions that are about the same things do not necessarily have the same truth-values. Certainly, Columbus's act of sailing the ocean does not exist in the same way today as it did in 1492; but what status, if any, can an act completed over 500 years ago be said to have today? To understand more fully what THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 199 200 HISTory oF PHIloSoPHy QuArTerly Aquinas thought to be the cause of a past-tense propositions' truth, we must investigate further what he meant by the "different status" that an object has when a past-tense proposition about it is true. In contemporary philosophy, there is a well-known debate about the existential status of nonpresent events. Presentists hold that only the present exists. The past and future have no actuality. They believe that this account of time best captures the real change that occurs in the temporal order. eternalists, on the other hand, think that the past and future exist on par with the present.11 For the eternalist, the terms present or now are indexicals that pick out the time that an utterance occurs. So when one says that an event is happening "now" or that it is "present," one is not stating that the event has some ontological privelege; rather, one is claiming that the event occurs at the same point on the continuum of eternally existing events as one's utterance.12 In the above passage from Aquinas, it appears that he is advocating an eternalist theory of time since he claims that those things that are past have a status.13 If Aquinas did in fact hold that the past has existence on par with the present, then there is a simple solution to the difficulty about the ontological grounds of essential truths whose subjects no longer exist. Although some of the creatures that we form essential propositions about do not exist at the same point that we do on the eternal continuum of past, present, and future objects, they still exist eternally and can serve as the grounds of the truth of our propositions. Although maintaining that the past eternally exists provides an easy solution to the difficulty under consideration, textual evidence shows that Aquinas did not in fact hold that past events exist. Throughout his corpus, there are several passages in which he expresses the view that the future and past are not on an ontological par with the present. In the De veritate, for example, Aquinas writes, "[T]hat which is future, in so far as it is future, and similarly, that which is past, does not exist."14 Moreover, the presupposition that the past does not exist underlies Aquinas's articulation of what the perfect past tense signifies. He writes in his Commentary on the Gospel of John that the perfect past tense "indicates that something has existed, is now determined, and has now ceased to be."15 These texts make clear that the "status" Aquinas claims that past things have cannot be construed to imply that past events exist. A remark Aquinas makes in his Commentary on the Metaphysics gives some insight into what he meant by apparently ascribing a status to the past. There, Aquinas claims that past events, although they do not have existence in the present, retain a kind of reality in the present since they once existed and true propositions can be formed about them at the present time. Aquinas writes, "[T]hat which is past now is in some way. I say this insofar as a past event has occurred or is past. For although the life of Caesar is not now in the present, it is, nevertheless, in the past since it is true that Caesar lived."16 Here Aquinas is clear that the life of Caesar does not exist in the present when the proposition Caesar lived is true. We can infer from what Aquinas said above in response to the objection regarding the truthvalues of tensed propositions that Aquinas would think that the living Caesar is the cause of the proposition Caesar lived. This implies that Aquinas thought that the cause of a past-tense proposition's truth did not have to exist at the times when that proposition is true. Although Caesar may not exist when Caesar lived is true, the living Caesar is considered by Aquinas to be the cause of the truth of this proposition because it was the cause of the truth of the corresponding presenttense proposition Caesar lives. Aquinas explicitly claims in his Commentary on the Nicomachean Ethics that the truth of a past-tense proposition depends on the truth of a corresponding present-tense proposition, which was true in the past: "the truth of past-tense propositions depends on the truth of presenttense propositions. Therefore, something was is true because something is was true."17 It is now true that "Socrates sat," for example, because at some earlier time, it was true that "Socrates sits." So, in causing Socrates sits to be true at time t1, Socrates causes Socrates sat to be true at every time after t1. The texts examined show that Aquinas is committed to the principle that the ontological grounds of any pasttense proposition Pp is the ontological grounds of its present-tense counterpart p. That which causes p's truth need not exist while Pp is true. All that is required for Pp's truth is that something did exist that caused the truth of p in the past. From this commitment of Aquinas's, it seems that we can fairly easily extrapolate his position on the grounds of the truth of essential propositions about creatures that have perished. If Aquinas holds that the living Caesar who no longer exists is a sufficient cause of the truth that Caesar lived, then it seems that the dinosaurs that once lived, but are now extinct, would be sufficient causes of the truth dinosaurs are sentient. To explicate this solution fully, we must examine Aquinas's views on the precise feature of reality that grounds the truth of an essential proposition while the subject that it is about exists. We must know, for example, what existing thing (or things) was required for the truth of the proposition dodo birds are sentient while dodo birds did exist in order to reconstruct Aquinas's thinking on the grounds for the truth of that same proposition after dodo birds have perished. THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 201 202 HISTory oF PHIloSoPHy QuArTerly iii. tHe cause of tHe trutH of essential ProPositions wHile tHeir subjects exist Aquinas never explicitly addresses the question of the grounding of essential propositions; however, his position can be inferred from a certain argument that he made for the unicity of substantial form. The question of whether a material substance had one or more substantial forms was fiercely debated at both oxford and Paris in the 1270s and 1280s.18 The debate centered on this issue: in any matter-form composite, does one substantial form or more than one substantial form account for the essential features that a substance has? For example, does one substantial form account for the fact that an animal is sentient and another account for the fact that it engages in vegetative activities and a third account for the fact that it is a body, or does one form alone account for the fact that the animal is sensitive, vegetative, and corporeal? This debate has much to do with our question about the ontological grounds of essential propositions. If one adopts the position that there is a plurality of forms that accounts for a being's essential features, then it seems that the composition of these forms will be the res to which essential propositions conform. For example, if there are two distinct forms that respectively cause a subject to be a sentient creature and to be a dog, then the truth of the proposition dogs are sentient will depend on these two forms being composed in reality. on the other hand, if one adopts the position that certain substances are both dogs and sentient in virtue of having one substantial form, then this form alone, and not any composition of forms, will be able to ground the truth of the proposition dogs are sentient. It is well known that Aquinas adopted the unicity of form position. He argued that if a substance had its essential features from distinct substantial forms, then these attributes could only be predicated of it accidentally.19 He thought that two distinct forms could never be ordered to each other in the way required for one to enter into the definition of the other as happens in essential predication. Aquinas is clear that whatever is not predicated accidentally is truly one in reality with that of which it is predicated.20 The truth of nonessential propositions is grounded by compositions in reality. A white thing is sweet is true only if there is some corresponding union in reality between a thing having the form of whiteness and the form of sweetness. essential propositions are different, though, according to Aquinas. one res, namely, a substantial form, grounds the truth of an essential proposition. In rejecting that there is a multiplicity of substantial forms in one substance, Aquinas is rejecting that it is true that man is an animal because two distinct forms, humanity and animality, are united in one being. The concepts signified by the words man and animal are distinct concepts, but the form that is signified by these concepts is one. In the proposition man is an animal, "man" and "animal" ultimately signify the same reality (res significata), namely, the one substantial form of man. Since the predicate and the subject in an essential predication both signify the same simple form, essential propositions are necessarily true. That which the subject signifies cannot be separated from that which the predicate signifies because they are one in reality.21 We have seen precisely what ontological reality grounds the truth of essential propositions while their subjects exist. Now we can apply Aquinas's reasoning about the grounding of past-tense propositions to formulate his account of how essential propositions remain true after their subjects have perished. It seems that since the substantial form of a creature was sufficient to ground the truth of essential propositions about the creature when it did exist, the creature's substantial form should also be a sufficient ground for these essential propositions even after it perishes. In discussing past-tense propositions, Aquinas claims that the ground of a past-tense proposition need not exist at the time that the past-tense proposition is true. The fact that it caused the truth of the corresponding present-tense proposition is a sufficient condition for its causing the truth of a past-tense proposition at a later time. So it seems that the form of a creature that once existed should be sufficient to cause the truth of essential propositions even if it does not exist at the time that these propositions are true. There is, however, an important difference between essential propositions and past-tense contingent propositions that may stand in the way of applying Aquinas's reasoning about past-tense propositions to essential propositions about creatures that have perished. iV. a releVant difference between essential ProPositions and Past-tense continGent ProPositions The difference that we must take into account between essential propositions and past-tense contingent propositions is their tense. recall that Aquinas claimed that although p and Pp have the same ontological cause of their truth, they do not have the same truth-values. He explained that this is because the cause of truth changes in its status. The cause of p's truth must have existed in the past in order to cause the truth of Pp. A presently existing object, which causes p's truth at the present time, is not sufficient to cause the truth of Pp at the present time. Similarly, if the cause of p's truth existed in the past but does not now exist, then it cannot cause the truth of p at the present time. An object must exist at time t to cause the truth of a present-tense contingent proposition at t. Aquinas's connecting the existential status of an object to the tense THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 203 204 HISTory oF PHIloSoPHy QuArTerly of the proposition whose truth it causes is intended to ensure that the truth-values of contingent propositions are able to change along with the real change in things. The living Caesar, for example, causes the truth of Caesar lives while he is alive. When Caesar dies, however, he undergoes a change and a corresponding change occurs in the truthvalues of tensed propositions about his life. What is at issue in the case of essential propositions, however, is how to guarantee that the truthvalue of the essential proposition does not change with the change in things. Aquinas maintains that essential propositions such as dogs are sentient are perpetually true, regardless of the generation and corruption of individual dogs. What is relevant about this proposition is that it is in the present tense. This seems to pose a difficulty to our attempt at reconstructing Aquinas's thinking on essential propositions about nonexistent subjects based on his views about past-tense propositions. It seems that a form of a dog that existed in the past does not provide sufficient ontological grounds for the truth of the proposition dogs are sentient after no forms of dogs exist. According to Aquinas's reasoning about tensed-contingent propositions, the truth that dogs are sentient can only be grounded by a presently existing form of a dog. A form of a dog that existed in the past is only able to ground the truth of past-tense propositions about dogs, for example, dogs were sentient. It seems that we cannot claim that present-tense essential propositions are true after their subjects perish in virtue of the object that caused the truth of these same propositions in the past. This difficulty can be addressed by considering what Aquinas says about the various functions of the present tense. Aquinas did not think that the present tense only had the function of signifying that there is a connection between a subject and predicate at the present time. In his Commentary on the Gospel of John, Aquinas explains that the present tense is the proper tense for designating eternal things: "But concerning the notion of the present, the present tense is most fitting to designate eternity, because it signifies that something is in act, which always belongs to eternal things."22 It seems that this passage would not be relevant to essential propositions about material objects since material objects do not exist eternally; rather they are generated and corrupted in time. It is important to realize, however, that Aquinas uses the word "eternal" in a number of ways. In its most proper sense, it refers to the atemporal existence that belongs to God.23 In a secondary sense, it is used to designate those things that exist perpetually.24 less frequently, Aquinas uses "eternal" to refer to universals.25 This final sense is relevant to understanding what the present tense of essential propositions signifies. Aquinas thought that universals are eternal not in the positive sense of existing at all times but in the negative sense of abstracting from all times and places.26 essential propositions signify a connection between subject and predicate that is eternal in this sense of abstracting from specific existential conditions. The proposition a dog is an animal does not assert that there is now an existing form of a dog and an existing form of animal that are one in reality at this present time, just as the contingent present-tense proposition a white thing is sweet asserts that there is an existing form of whiteness and an existing form of sweetness that now coincide in the same subject. What the proposition a dog is an animal asserts is that there is a connection between the form of dog and the form of animal that does not depend on the coincidence of being a dog and being an animal in any specific substance localized to a certain time and place. The connection between the subject and the predicate in an essential proposition is a formal connection between the forms signified by the subject and the predicate. We saw earlier that the ontological basis for this necessary connection between the forms signified in an essential proposition is their identity in reality. The connection between them does not depend on any particular subject's possessing both forms since those forms are identical. Accordingly, the truth of essential propositions abstracts from when and where they are uttered. Since the connection between forms that are related to one another in an essential proposition does not depend on the fact that they conicide in a particular subject at a certain time or place, a form that exists at any time is a sufficient cause of the truth of all essential propositions about it, regardless of their tense.27 It is true that, like Socrates's sitting, the form of a dog can pass in and out of existence. The truth that the form of a dog causes, however, does not change in status with the cessation of the form as the truths caused by Socrates's sitting change after it ceases to exist. This is because, unlike the connection between Socrates and sitting, the connection between dog and its essential attributes does not depend on any particular coincidence in a material object at a specific place and time. Another way to think of the difference between essential and nonessential propositions is like this: contingent nonessential propositions are implicitly indexed to a particular time since they express connections that are merely coincidental. So the proposition asserting that Socrates sat can be expanded as Socrates sat at tn. Since this proposition's truth is indexed to a particular time, the time at which the object that causes its truth exists is crucial to its truth-value. Socrates's act of sitting at t2, for example, cannot cause the truth of the proposition Socrates sat at t4. Since essential propositions assert a formal, rather than a coincidental, THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 205 206 HISTory oF PHIloSoPHy QuArTerly connection between subject and predicate they are not similarly indexed to times. The essential proposition that expresses the connection between humanity and animality, for example, can be expanded as such: man is an animal abstracting from all places and times. Since this proposition only expresses a connection between attributes and not a specific time at which this connection exists, if it has a sufficient ontological cause at any time tn, then it will also be true at all other times. An essential proposition is true in virtue of its having adequate ontological grounds at any time, rather than at some specific time. V. wHy not tHink tHat God's ideas Ground tHe trutH of essential ProPositions? As mentioned in the introduction of this paper, many who are familiar with Aquinas's teaching may be inclined to think that God's ideas should have some role in grounding truths about essential propositions. In certain contexts, Aquinas describes the nature of a creature as existing in God and as prior to and explanatory of the nature as it exists in the actual creature. In question one, article one of the eighth Quodlibetal Question, Aquinas is pressed with the seemingly odd question of "whether the number six, according to which all creatures are said to be perfect, is the creator or a creature."28 There Aquinas explains that there is a hierarchy of the various ways in which a nature can be considered. At the bottom of the hierarchy is the nature as understood in the human intellect. Above that is the nature as it exists in created things. Prior to both of these is the nature absolutely considered, which is indifferent to being in the mind and in things. At the top of the hierarchy is the nature as it exists in the divine intellect. Aquinas claims that the natures that are prior explain why the posterior natures have the features that they do. Human nature as it exists in individuals has the features that it does because of human nature as it exists in the divine intellect.29 If the nature as it exists in God's intellect is prior to and explanatory of the natures that exist in individual creatures, it seems that it must be the ultimate reality that guarantees the truth of necessary predications about creatures. Whether or not dinosaurs exist, dinosaur nature exists in God, and so claiming that this nature grounds all essential truths about dinosaurs neatly explains how these truths can remain true after all dinosaurs have perished. Although this view appears to have some textual support and philosophical merit, we must consider whether it is on the whole a solution that is faithful to Aquinas's thought. Aquinas addresses another question that is related to the issue of whether the natures of creatures existing in God or in the creatures themselves are the ground of the truth of necessary propositions. In the De veritate, he asks "whether things are more true in the Word or in themselves."30 By "the Word," Aquinas means the second person of the Trinity. Things as they are "in the Word" are things as they exist in God. In answering this question, Aquinas writes that "the name 'man' is more truly predicated of the thing which is in its proper nature than that which is in the Word."31 earlier in this article he explains why names refer more properly to things existing in their own nature, as opposed to in the Word: "on account of the distance of the caused thing from its cause, something is truly predicated of the caused thing that is not predicated of its cause. . . . [T]his indeed only happens when the mode of the causes is more sublime than those things that are predicated of the effects.32 When a cause causes an effect that falls short of its own perfection, the effect possesses attributes that differ from the cause. Accordingly, certain names will apply truly to the effects but not to the cause. Although the nature as it exists in God's intellect has a causal role in producing the natures as they exist in creatures, certain names are predicated more truly of the natures as they exist in creatures since the nature in God has far more perfection than these names imply. later, in the Summa Theologiae, Aquinas takes up the issue of whether things existing in the divine mind are more truly what they are than those things existing in themselves.33 There Aquinas explains that all things have uncreated being in the divine mind because God's ideas have no being distinct from God's own being. Things existing in themselves have created being, which is less noble than God's own uncreated being. yet, Aquinas claims that natural things are more truly what they are when they exist in themselves because it belongs to their natures to be material: "Just as a house has being more nobly in the mind of the artificer than in matter, but neverthless 'house' is said more truly of that which is in matter than that which is in the mind because the former is a house in act, while the latter is a house in potency."34 Aquinas thinks it follows from the claim that an actually existing creature is more properly a thing of its kind that the term that is used to signify the kind applies more properly to material creatures than to the divine exemplar of these creatures. The term dog, for example, is more truly a name for a material creature that barks and chases its tail than for the divine essence since the material dog actually has the features that are proper to a dog. We can now see how Aquinas's responses to the questions examined above bear on the question of whether God's ideas ground essential truths about creatures. Although the nature existing in the divine mind may be prior to and explanatory of created natures, we can quesTHe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 207 208 HISTory oF PHIloSoPHy QuArTerly tion whether these ideas are the being to which essential propositions about creatures correspond because, first, the natures in creatures are more truly things of their kind than the nature as it exists in God's mind and, second, because the terms of propositions primarily signify natures in creatures. It seems that the truth of a proposition about a given kind should be grounded by that which is most truly the thing of this kind, regardless of whether there is something else that is causally responsible for it, which is not truly a thing of this kind. Consider this analogous example: Suppose that an architect drew a blueprint from which a house was constructed. Although this blueprint of a house is explanatorily prior to the actual house, it seems indisputable that the house itself is what grounds various true propositions about the house, for example, the house has a chimney, the house has six bedrooms. If the house were to burn down in a fire, we would appeal to the house that once existed-not the surviving blueprint-to ground the truths about the house that perished. The case is similar with natures in the divine intellect and in created things. Since the created natures are things that the terms of propositions signify, it seems that created natures must be the ground of the truth of propositions about creatures. one might argue that the fact that the terms of propositions signify created natures does not give evidence that the created natures themselves, rather than divine ideas, are the ontological grounds of propositional truth since we can come up with examples of cases in which beings that are not immediately signified by the terms of a proposition nevertheless cause its truth. The cause of the truth of the proposition Socrates is white, for example, is the composition of the form of whiteness with Socrates's matter. The term Socrates does not signify Socrates's matter, yet Socrates's matter is an element of the composition that causes this proposition's truth. When one reflects on what Aquinas understands an essential proposition to be, one will see, however, that Aquinas himself would not accept that essential propositions could be grounded by something other than what their terms signify. Aquinas's reasoning in the context of arguing against the multiplicity of forms shows that he thought that the necessity of an essential proposition was guaranteed by the fact that the subject and the predicate signify the same thing in reality. Man is rational, for example, is necessarily true because "man" and "rational" signify differing concepts of what is one in reality. The unity of the thing signified by the terms of a proposition grounds this proposition's necessary truth. An essential proposition, therefore, cannot be grounded by a reality that its terms fail to signify. Since the terms of essential propositions about creatures do not signify God's ideas, God's ideas cannot be the ground of the truth essential propositions. Vi. conclusion Aquinas's solution to the difficulty of how essential propositions remain true after their subjects perish is certainly an economical one. It does not involve postulating or appealing to any other beings besides the creatures that essential propositions are about. We can explain the truth of the proposition dodo birds are sentient, for example, solely by appealing to the dodo birds that once existed. Some might claim that the simplicity of Aquinas's solution comes at the cost of breaking down the link between truth and being since it follows from it that not every true proposition conforms to an existing being. It is true that Aquinas's account of how essential propositions (and past-tense contingent ones) remain true after their subjects perish implies that not every true proposition corresponds to a being that exists at the time when it is true. Still, Aquinas is able to maintain that there is a fundamental link between truth and being since every true proposition is ultimately traced back to some being that once existed as the cause of its truth. This study has broader implications for how we should understand Aquinas's own claims about the link between truth and being. Throughout his discussions on truth, Aquinas repeatedly emphasizes the connection between truth and being, by making statements such as this one: "To every true act of understanding there must correspond some being."35 This analysis of Aquinas's thought on essential truths about creatures that have perished reveals that he did not believe there is a one-to-one correspondence between true propositions and presently existing things. rather, he held a more moderate view that allows for some propositions to have their truth in virtue of beings that existed in the past. When Aquinas's view on this point is clarified, some significant problems that appear to follow from his conception of truth dissolve.36 University of St. Thomas NoTeS All translations are my own. Aquinas's texts are quoted from Sancti Thomae Opera omnia, leonine ed. (rome, 1882–) unless otherwise noted in the first quotation of a particular work. 1. In III Sent., d. 2, q. 2, a.3 (ed. F. M. Moos [Parisiis: P. lethielleux, 1956]): "nulla natura habet esse nisi in supposito suo. Non enim humanitas esse potest nisi in homine." Aquinas is clear elsewhere that natures are created by God with their supposits and in no way preexist them. See, for example, De Potentia 3.5 THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 209 210 HISTory oF PHIloSoPHy QuArTerly ad 2 (ed. P. M. Pession, 10a ed. [Taurini-romae: Marietti, 1965]: "Ad secundum dicendum, quod ex hoc ipso quod quidditati esse attribuitur, non solum esse, sed ipsa quidditas creari dicitur: quia antequam esse habeat, nihil est, nisi forte in intellectu creantis, ubi non est creatura, sed creatrix essential." De Potentia 3.1 ad 17: "Ad decimum septimum dicendum, quod Deus simul dans esse, producit id quod esse recipit: et sic non oportet quod agat ex aliquot praeexistenti." 2. De ver., 1.2 ad.1: "eo quod cuilibet intellectui vero oportet quod respondeat aliquod ens." 3. Aquinas explicitly claims that essential propositions are perpetually true. See, for example, In Meta. IX.11, n. 1900. 4. Disputatio Metaphysica XXI, section 12, para. 38: "si, ablata existentia, perit essentia, ergo propositiones illae in quibus praedicata essentialia de re praedicantur non sunt necessariae neque perpetuae veritatis . . . omnes veritates circa creaturas essent contingentes, unde non posset de creaturis esse scientia, quia haec solum est de veritatibus necessariis." 5. Ibid.: "occurrit tamen statim trita difficultas superius tacta." For a summary of the debate among the neo-Scholastics on this issue, see Jeffrey Coombs, "The ontological Source of logical Possibility in Catholic Second Scholasticism" in The Medieval Heritage in Early Modern Metaphysics and Modal Theory, 1400–1700, ed. russell l. Friedman (Dordrecht: Kluwer Academic Publisher, 2003), 191–229. 6. See, for example, Norman Wells, "Descartes and the Scholastics Briefly revisited," New Scholasticism 2 (1961): 187–90. 7. recently, a few dissertations and articles have attempted to explain how Aquinas grounded modal truths. each of the following studies has argued that some aspect of God-namely, his essence, ideas, or power-grounds the truth of at least some necessary propositions about creatures: Amy Karofsky, "The ontology of Alethic Modalities in Aquinas, Suarez, and leibniz" (PhD diss., university of Virginia, 1997); Brian leftow, "Aquinas on God and Modal Truth," The Modern Schoolman 82, no. 2 (2005): 171–200; and James Stone, "The Foundation of universal and Necessary Propositions in Select Writings of Thomas Aquinas" (PhD diss., Fordham university, 2008). In his A Thomistic Account of Truthmakers for Modal Truths (PhD diss., St. louis university, 2008), Timothy Pawl argues that necessary truths do not have objects that ground them. rather, a necessary truth is true in virtue of its complementary possibility claim lacking a "truthmaker." For example, it is true that necessarily man is an animal because no power, including God's, grounds the truth of the claim possibly it is not the case that man is an animal. Pawl does not argue that Aquinas explicitly held this view, but only that this view is consistent with his other doctrines, which, according to Pawl, underdetermine his view of modal "truthmakers." 8. This question had important theological consequences. In book I, distinction 41, of his Sentences, for example, Peter lombard holds that propositions that vary only according to tense must assert the same content because, if this were to be denied, the prophets who uttered that Christ will be born would not be asserting the same thing believed by later Christians who confessed that Christ has been born. The school of Bernard of Chartres adopted this position, and its advocates came to be known as nominales. on this, see M. D. Chenu, "Grammaire et théologie aux XIIe et XIIIe siècles,' Archives d' histoire doctrinale et littéraire moyen âge 10 (1936): 5–28; and W. C. Kneale and M. Kneale, The Development of Logic (oxford: The Clarendon Press, 1962), 238–41. 9. Summa Theologica (ST) Ia.16.8 arg. 4: "Praeterea, ubi est eadem causa, et idem effectus. Sed eadem res est causa veritatis harum trium propositionum Socrates sedet, sedebit, et sedit. ergo eadem est harum veritas. Sed oportet quod alterum horum sit verum. ergo veritas harum propositionum immutabiliter manet." 10. ST Ia.16.8 ad 4: "Ad quartum dicendum quod sessio Socratis, quae est causa veritatis huius propositionis, Socrates sedet, non eodem modo se habet dum Socrates sedet, et postquam sederit, et antequam sederet. unde et veritas ab hoc causata, diversimode se habet; et diversimode significatur propositionibus de praesenti, praeterito et futuro. unde non sequitur quod, licet altera trium propositionum sit vera, quod eadem veritas invariabilis maneat." 11. For more on these theories and suggestions for further reading, see Ned Markosian's entry "Time" in the Stanford Encyclopedia of Philosophy (http:// plato.stanford.edu/entries/time/). 12. See Michael J. loux, Metaphysics: A Contemporary Introduction, 2d ed. (New york: routledge, 2002), 221–22. 13. Some claim that Aquinas held the eternalist view of time because, in several places, he claims that God knows which contingents obtain because all contingents are eternally present to him. See, for example, De ver. 2.12 co. For an argument that this view of Aquinas's entails that all temporal events exist eternally, see William Craig, "Was Aquinas a B-Theorist of Time?" The New Scholasticism 59 (1985): 475–83. In De ver. I.5 ad 11, Aquinas explicitly claims that things do not exist eternally, although God eternally knows them. recently Brian leftow, Brian Shanley, and Kevin Staley have given different accounts of how Aquinas's views on God's knowledge do not imply that all created objects have eternal existence. See Brian leftow, "Aquinas on Time and eternity," American Catholic Philosophical Quarterly 64, no. 3 (1990): 387–99; Brian Shanley, "eternal Knowledge of the Temporal," American Catholic Philosophical Quarterly 71, no. 2 (1997): 197–224; and Kevin Staley, "omniscience, Time and eternity: Is Aquinas Inconsistent?" The Saint Anselm Journal 3, no. 2 (Spring 2006): 9–16. 14. De ver. 1.5 ad 6: "illud quod est futurum, in quantum est futurum, non est, et similiter quod est praeteritum . . ." See Super Io. I.1 for an additional example of Aquinas's claim that the past does not exist. For more on his views on the nature of time, see In Physic. VI.7. 15. Super Io. 1.1 (ed. Marietti): "praeteritum autem perfectum designat aliquid extitisse, et esse iam determinatum, et iam defuisse." THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 211 212 HISTory oF PHIloSoPHy QuArTerly 16. In Meta. VI.3, n. 1199 (ed. Marietti): "hoc quod praeteritum est iam est secundum aliquem modum. Hoc autem dico inquantum est factum vel praeteritum. licet enim vita Caesaris non sit nunc ut in praesenti, est tamen in praeterito. Verum enim est Caesarem vixisse." 17. In Ethic. I.15 n.9: "veritas autem propositionis de praeterito dependet ex veritate propositionis de praesenti. Ideo enim aliquid verum est fuisse, quia verum fuit esse." 18. For an excellent overview of this debate and references to secondary literature, see J. F. Wippel, The Metaphysical Thought of Godfrey of Fontaines (Washington, D.C.: The Catholic university of America Press, 1981), 314–47. 19. See ST Ia.76.3; Summa contra Gentiles (ScG) II.58; and Quodlibetal Question (QQ) De A., 11, co. 20. Meta. IV.2 n. 7: "Quaecumque duo praedicantur de substantia alicuius rei per se et non per accidens, illa sunt idem secundum rem: sed ita se habent unum et ens, quod praedicantur per se et non secundum accidens de substantia cuiuslibet rei" (italics mine). See also Meta. IV.7 n. 628. 21. John o'Callaghan has made the point that, for Aquinas, the unicity of substantial form is the metaphysical grounding for the unity of definition, as well as the necessity of essential predications. See his "Aquinas's rejection of Mind, contra Kenny," The Thomist 66 (2002): 43 and 46; and his "Imago Dei: A Test Case for St. Thomas's Augustinianism," in Aquinas the Augustinian, ed. M. Dauphinais, B. David, and M. levering (Washington D.C.: The Catholic university of America Press, 2007), 100–44, at 123. 22. Super Io. 1.1: "Sed quantum ad rationem praesentis competit maxime ad designandum aeternitatem praesens tempus, quod signat aliquid esse in actu, quod semper convenit aeternis." 23. See, for example, ScG I.15. 24. This is the sense in which "eternal" is used in the discussion about the eternity of the world. The sense in which the world could have possibly been eternal differs from the sense in which God is eternal since the world, even being eternal, would still have created existence from God that is subject to motion and change. See Aquinas's De aeternitate mundi. 25. In I Sent. 19.5.3 ad 3. 26. ST Ia.16.7 ad 2: "Ad secundum dicendum quod aliquid esse semper et ubique, potest intelligi dupliciter. uno modo, quia habet in se unde se extendat ad omne tempus et ad omnem locum, sicut Deo competit esse ubique et semper. Alio modo, quia non habet in se quo determinetur ad aliquem locum vel tempus, sicut materia prima dicitur esse una, non quia habet unam formam, sicut homo est unus ab unitate unius formae, sed per remotionem omnium formarum distinguentium. et per hunc modum, quodlibet universale dicitur esse ubique et semper, inquantum universalia abstrahunt ab hic et nunc. Sed ex hoc non sequitur ea esse aeterna, nisi in intellectu, si quis sit aeternus" (PA 1.42 n. 6). Armand A. Maurer discusses this passage and others in his "St. Thomas and eternal Truths," Medieval Studies 32 (1970): 91–107, which is also reprinted in his Being and Knowing: Studies in Thomas Aquinas and Later Medieval Philosophers (Toronto: PIMS, 1990). 27. Although Aquinas does not think that the present or continuing existence of a form is necessary for a true proposition to be formed about it, he would think that it is necessary for a form to have existed at some time in order for it to be the subject of a true proposition. essential propositions are not completely without existential import for Aquinas. 28. QQ. 8.1.1 29. QQ. 8.1.1 co. For literature on this text, see Kevin White's "Creation, Numbers, and Natures," in Medieval Masters: Essays in Memory of Msgr. E. A. Synank, ed. r. e. Houser (Houston: Center for Thomistic Studies, 1999), 179–90. 30. De ver. 6.4. For literature on this text and those that follow in this section, see Jan Aertsen, Nature and Creature: Thomas Aquinas's Way of Thought (Brill: leiden, 1988), 180–82. This section of his book is titled "Are Things More True in Themselves Than in the exemplars?" 31. De ver. 4.6 co.: "verius enim praedicatur homo de re quae est in propria natura quam de ea secundum quod est in Verbo." 32. Ibid.: " et propter istam distantiam causae a causato aliquid vere praedicatur de causato quod non praedicatur de causa . . . quod quidem non contingit nisi quia modus causarum est sublimior quam ea quae de effectibus praedicantur." 33. ST Ia.18.4 ad 3. 34. Ibid. 35. De ver, 1.2 ad.1: "eo quod cuilibet intellectui vero oportet quod respondeat aliquod ens." 36. I am grateful to Stephen Dumont, Alfred Freddoso, John o'Callaghan, and Timothy Pawl for helpful comments and conversations regarding this paper. THe PerPeTuAl TruTH oF eSSeNTIAl ProPoSITIoNS 213 x