Last Thoughts on Whether the Natural Philosopher Escapes the Eternity of Time
/By John F. X. Knasas, Professor emeritus
Center for Thomistic Studies
University of St. Thomas, Houston, Texas
The issue remains whether the Thomistic natural philosopher has the wherewithal to defuse Aristotle’s argument for the eternity of time. As has been noted, the issue is not arcane but has implications for how, over the centuries, the philosophical sciences have been taught ad mentem Sancti Thomae. Prof. Brungardt has argued that just by logic the natural philosopher can critique Aristotle’s argument. I understand him to mean that the argument fails internally. No need exists to bring in anything extraneous. I have argued that the argument from time is recast into a form that is then criticized metaphysically in paragraph 990 of the Physics commentary. In his last post Brungardt fears that we are embarrassing ourselves by continuing an argument on an issue that others say is unsolvable and is becoming “Thomistically legislative” because of its close scrutiny of the texts. These fears are groundless. I do think that the issue of how physics is related to an embryonic metaphysics has been approached from implications in how Aquinas critiques the Aristotelian arguments from the eternity of motion. Should not the debate continue by assessing that new angle? Also, one cannot read philosophical texts without thinking philosophically. Studying philosophical texts is not like an actor memorizing his lines.
As our exchanges note, Aquinas originally criticizes the argument for the eternity of time at para. 983 of the Physics commentary for its comparison of the now of time to the point of a line. The comparison obviously fails because there are points of a line before and after which there is no line. The now of time need not be preceded or followed by other nows. Hence, the argument does not prove the eternity of time on the basis of the analogy between the now and the point. So far Aquinas’ critique is “logical” because the critique stays within the context of the argument. In other words, just by its own assertions, the argument invites the criticism that it assumes what it wants to prove.
Brungardt has now argues that this argumentation for the eternity of time and the logical critique of it are definitive. His reason is that the opening lines of para. 990 reiterate both the argument and the critique. The later section of 990 that I appealed to and which brings up “imaginary time” simply explains how someone could have got it all wrong and believed that time was eternal. In this post I want to make some remarks about Brungardt’s new text.
At the start of 990, Aquinas says:
But the statement that every “now” is both a beginning and an end should not be conceded, unless it be also granted that motion always existed, so that every indivisible of motion (which is called a “moment”) should be both a beginning and an end of motion, for the “now” is to the moment as time is to motion. If, therefore, we suppose [Si ergo ponitur] that we can take a first indivisible in motion before which nothing of motion existed, we can also take some “now” in time before which there is no time.
There is no mention of the analogy of the now to a point. Nevertheless, the crucial claim that every now is a beginning and end is made by reference of the now of time to the moment of motion. That reference is to no avail because we can suppose that motion has not always existed. Hence, there can be first indivisible in motion and so a first now of time.
No doubt there are similarities here to 983. Just as 983 compared the now to a point, 990 references the now to the moment, to the subject of time, as Brungardt says. Also, the critiques of 983 and 990 focus on the correctness of the analogies. 983 notes that some points are not middles, 990 insists that there can be a first indivisible, or moment, in motion.
How does Aquinas know that we can question that every moment is a middle? What warrants us to suppose that there can be a first indivisible in motion? In case of the analogy of the now to the point, the basis for questioning the analogy was obvious - our familiarity with lines. From whence do we derive a familiarity with motion to suppose that motion could begin without motion?
Before I note Aquinas’ reply, what does Brungardt answer? Brungardt claims that the now has the character of a middle because of its subject, the moment of motion, not because of its nature, or ratio. Brungardt’s thinking is so succinct that it is difficult to understand what he is getting at. I could venture guesses, but there is a good chance that my guesses would be incorrect. Without Brungardt’s elaboration, I cannot speak to his claims.
So, what does Aquinas say to neutralize the reasoning? Like Brungardt, does Aquinas appeal to the ratio of the now, or to something else? Just earlier in paragraph 987 in which Aquinas begins his reply to Aristotle’s three arguments for motion’s eternity, Aquinas says that it has already been pointed out that the production of all being by the first cause of being is not a motion: “productio totius esse a causa prima essendi non est motus.” Hence, it does not follow that there was change before change. We can assume a moment before which nothing of motion existed, that is, a first indivisible in motion.
Is this knowledge of a first cause of being a theological notion and so the critique is one of religious faith? Yes, but not simply. In the first lectio of Physics VIII, 914, Aquinas speaks of the primo principio essendi as both a point of his religious belief and something Aristotle proves in In II Meta. 296, the supremely true supreme being for all existents: “maxime verum et maxime ens est causa essendi omnibus existentibus.”
Has not Aquinas neutralized the above 990 version of the time argument by an already in-place metaphysical knowledge of a creator? Here too Aquinas’ critique remains metaphysical. The critique is not simply logical, or internal. Because the analogy of the now to the point has been replaced by the reference of the now to the moment, it is no longer obvious that the now is not always a middle. Nothing other than metaphysics is indicated to introduce us to the idea of a first indivisible in motion and so to the possibility of a now before which there is no time. Whether one agrees with it or not, that is Aquinas’ thinking.
Brungardt and I can further discuss what this metaphysical critique means for interpreting the rest of paragraph 990, as I mentioned earlier. But it does show that Aquinas’ critique is more than internal or logical. Unlike the critique of 983, the critique of 990 goes outside the argument to metaphysics. Evidently, there are two ways of begging the question. One way is by circularity as in 983. Another way is by failing to consider all the alternatives as in 990. Whether the two ways of begging the question produce the same argument or different arguments I leave to further discussion.
The above noted reference by Aquinas to In II Meta warrants a word. There Aquinas argues that the celestial spheres have a cause not only of their motion but also of their being. The reason is because everything that is composite in nature and participates must ultimately have as its causes those things which are through essence: Omnia composita et participantia, reducantur in ea, quae sunt per essentiam, sicut in causas. Except for the use of the plural, this remark echoes the causal reasoning of the De Ente et Essentia, ch. 4, in which Aquinas remarks that what belongs to a thing is caused either by the principles of the thing or by something else. Into this principle Aquinas inserts esse as something had by the thing, and he traces esse to a first cause whose essence is its existence, esse tantum. This apparent liaison with the De Ente suggests that the De Ente is the presupposed framework for Aquinas’ reading of Physics VIII. From that metaphysics Aquinas is generating all of the possibilities that he employs to neutralize the arguments for the eternity of motion.
Before my final word, some quick comments on two other of Brungardt’s remarks. Regarding the In II Phys. 175 text that speaks about the rational soul, Brungardt cannot see a possible identity of a Thomistic quomodo (how something is) and Thomistic an sit (whether it is). Sometimes, however, a question of whether something is so can be placed in the form of a how-question. An atheist can ask a theist “How is God existent?” in the sense of a demand for proofs of God’s existence. Also, I would add that the progression of paragraph 175 from how the rational soul is separable to what it is according to its separable essence suggests that one is going from a that it is to a what it is. Second, Brungardt interprets Aquinas to say that Aristotle’s natural philosophy opponents in the Physics are answered by ad hominem arguments, that is, by answering them on their own terms. But the answer in para. 987, and cited by Brungardt himself, is in terms of categories of Aristotle’s natural philosophy.
Finally, I need to comment on a remark that Brungardt makes at the start of his last post. Brungardt says that my reflections “ultimately call into question the worth of pursuing natural philosophy today.” I surmise that this supposed conflagration is that from which Brungardt says he is escaping. I am not sure from where Brungardt derives this idea, but I insist that the charge is profoundly inaccurate. Nowhere do I mention it and nowhere does what I say imply it. I thought that I was saving natural philosophy from error, not destroying it. Moreover, as I explained in chapter 7 of my book that began this debate, the Thomistic notion of esse is not so radically prior to the thing that the thing has no role to play in respect to esse. Hence, the De Ente reasoning can be made more full and robust. By an analysis of the thing precisely as mobile, the natural philosopher elaborates both intrinsic and extrinsic conditions for the thing and so for esse. The De Principiis Naturae of Aquinas remains in effect. In my Thomistic Existentialism, I welcome reflections of natural philosophy. There is no need for the natural philosopher to do any escaping for fear of his very life.