At the start of chapter 7 of her (1749) Commentary on Newton's Principia, Émilie du Châtelet treats Newton as a decisive breakthrough in generating "some knowledge" of comets' "nature." Indeed, Newton had closed the first edition of the Principia with one of his crowning achievements: a (somewhat clunky) means to calculate the elliptical orbits of comets before ending on some speculative remarks on the ways comets maintain a kind of inter-stellar commerce and are possible sources of life. Du Châtelet then writes, "Seneca seemed to have had an inkling of what would one day be discovered about these celestial bodies, but the seeds of the true principles that he had sown were not allowed to grow by the doctrine of the Peripatetics, who, transmitting from century to century the errors of their master, maintained that comets were meteors and temporary fires." (Translated by Isabelle Bour & Judith P. Zinsser, 337-8) Without explaining Seneca's views, Du Châtelet treats Seneca as a distant and historically uninfluential predecessor to Newton. Because she does not explain in what way Seneca anticipated Newton, we may infer that the point of the passage seems less designed to give credit to Seneca as it is to castigate the Scholastics.*
Some searching on the internet made me realize that Du Châtelet is alluding to chapter 7 of Natural Questions, which is devoted to comets. This book targets (inter alia) Aristotle's views on comets. And so one way to understand Du Châtelet is that she is suggesting like a good Enlightenment thinker that even when the seeds of the truth are available, slavish obedience to intellectual authority will displace the germs that may ripen to fruition in a more open intellectual environment. But Seneca's chapter on comets is more interesting than these remarks indicate.
In the closing lines of Seneca's book [well, the original order--this has come under attack], Seneca suggests his own day and age is a kind of dark ages.** For Seneca describes the way his age is full of moral corruption and licentiousness. He then concludes with:
[In our times] There is no interest in philosophy. [Philosophiae nulla cura est.] Accordingly, so little is found out from those subjects which the ancients left partially investigated that many things which were discovered are being forgotten. But, by Hercules, if we applied ourselves to this with all our might—if youth soberly applied itself to it, if the elders taught it and the younger generation learned it—we would scarcely reach to the bottom where truth is located, which we now seek on the surface of the earth and with slack effort. (Seneca, Natural Questions VII:31)
Seneca's is a call to arms to subsequent generations to study nature (in context 'philosophy' clearly means natural philosophy). But, unusually, rather than promising quick, complete knowledge, he implies not just that his own generation barely has knowledge of nature, but that such knowledge is a distant prospect. Now, this intimates the idea of open-ended inquiry. But I say that because these closing lines echo one of the great set pieces of the chapter, which is worth quoting in full.
Why, then, we marvel at comets, such a rare spectacle in the universe, are not yet grasped by fixed laws and that their origin and end are not known, when their return is at vast intervals? [Quid ergo miramur cometas, tam rarum mundi spectaculum, nondum teneri legibus certis nec initia illorum finesque notescere, quorum ex ingentibus intervallis recursus est?] It has not yet been fifteen hundred years since Greece
Numbered the stars
And gave them names.
And yet there are many nations today that know the sky only by its face and do not yet understand why the moon lacks fulness and why it is obscured in an eclipse. Among us, too, only recently did science produce definite knowledge in these matters. The time will come when diligent research over very long periods will bring to light things which now lie hidden. A single lifetime, even though entirely devoted to the sky, would not be enough for the investigation of so vast a subject. What about the fact that we do not divide our few years in an equal portion at least between study and vice? And so this knowledge will be unfolded only through long successive ages. There will come a time when our descendants will be amazed that we did not know things that are so plain to them... Some day there will be a man who will show in what regions comets have their orbit, why they travel so remote from other celestial bodies, how large they are and what sort they are. Let us be satisfied with what we have found out, and let our descendants also contribute something to the truth...How many animals we have learned about for the first time in this age; how many are not known even now! Many things that are unknown to us the people of a coming age will know. Many discoveries are reserved for ages still to come, when memory of us will have been effaced. Our universe is a sorry little affair unless it has in it something for every age to investigate. Some sacred things are not revealed once and for all. Eleusis keeps in reserve something to show to those who revisit there. Nature does not reveal her mysteries once and for all. We believe that we are her initiates but we are only hanging around the forecourt. Those secrets are not open to all indiscriminately. They are withdrawn and closed up in the inner sanctum. This age will glimpse one of the secrets; the age which comes after us will glimpse another.--Seneca Natural Questions VII.25
So, Seneca admits that genetic and final cause(s) of comets are not known. But he is fairly confident that these will be known some day and that comets have law-governed orbits that will make them return eventually. This does anticipate Newton, as Du Châtelet suggests. Seneca prognosticates (prophecies?) a day in which a science of comets is possible. He does so by embedding it, first, in a larger narrative, in which he dates the birth of (taxonomic) astronomy fifteen hundred year earlier (ca 1400bc) in Greece (surprisingly not Babylonia or Egypt, although he is aware of their interest in the sciences). He notes that this science has made progress since including knowledge of how the different orbits produce phenomena like eclipses and the phases of the Moon. He notes, too, that this knowledge has not been widely dispersed among different peoples.
After having created this historical baseline of the growth of astronomical knowledge, second, he suggests that (a) with time and (b) the division of labor (c) lots more such knowledge will be attained, including (d) entirely unforeseeable knowledge, that (e) will seem entirely obvious to future generations so that (f) they will look back at Seneca's time as ignoramuses ("we believe that we are her initiates but we are only hanging around the forecourt." ). But, (g) there is no reason to think the enterprise of knowledge ever comes to an end ("unless it has in it something for every age to investigate").
This set of commitments (a-g) is characteristic of the idea of open-ended scientific progress. It will be recovered by Bacon and codified by 18th century Newtonians. I am most struck by (f) because once science has a history, every age tends to think of itself as a knowing age, and it is hard to imagine that one's own age will not look impressive to future ones (although it is a conceit of some science fiction like Star Trek)
Now, the reasons behind (g) are not entirely obvious. He makes it sound as if it is property of nature's majesty that it can never be fully known. But, it makes sense if, as I think it does, Seneca's line of argument presupposes that he thinks it is infinite in some (at least temporal) sense. He is clear about that in Letter 36, "none of the objects which vanish from our gaze and are re-absorbed into the world of things, from which they have come forth and are soon to come forth again, is annihilated; they merely end their course and do not perish." (Some -- I am not so sure -- see in this the idea of eternal return, an idea familiar to Seneca from Plato's Laws, book 3.) The universe does not perish, and presumably must take on infinite number of configurations awaiting the gaze(s) of future inquirers.
*Because of Adam Smith I had been discouraged from exploring Seneca's writings on astronomy. Smith has proven to be a reliable historian of astronomy and a reliable historian of the history of astronomy. In his "History of Astronomy," Smith castigates Seneca, whom he acknowledges is a decent historian of Greek astronomy, for failing to mention Hipparchus' heliocentric theory. In fact, in context, Smith uses this omission as an example of the decline of the study of astronomy in Roman times. In fact, he treats Seneca's era as a kind of dark ages, where there was "supercilious and ignorant contempt too, with which at this time they regarded all mathematicians, among whom they counted astronomers, seems even to have hindered them from enquiring so far into their doctrines, as to know what opinions they held." (Astronomy, 4.18, p. 65). Okay, let's return Du Châtelet.
** This may be we Smith's source on the idea that the Romans had no interest in mathematical sciences.
Comments