Since for everything that has come into being destruction is appointed, not even such a fabric as this will abide for all time, but it shall surely be dissolved, and this is the manner of its dissolution. Not only for plants that grow from the earth but also for animals that live upon it there is a cycle of bearing and barrenness for soul and body as often as the revolutions of their orbs come full circle, in brief courses for the short-lived and oppositely for the opposite; but the laws of prosperous birth or infertility for your race, the men you have bred to be your rulers will not for all their wisdom ascertain by reasoning combined with sensation, but they will escape them, and there will be a time when they will beget children out of season. Republic, Book 8, 546ab, Translated by Paul Shorey.
In the quoted passage, Socrates confronts (recall here, and here) the limits of his eugenic, breeding program. I tend to describe it (somewhat anachronistically) as his recognition that sexual desire among the carefully, artificially selected beautiful-of-mind-and-body-guardians cannot be controlled and falls outside scientific cognition. At one point, fairly recently, Eric Brown, a distinguished philosopher, who I have looked up to my whole academic career, objected to this characterization as Straussian. (It was not intended as a compliment.) Rather (and I summarize informally) Socrates claims that the cause of the decline of Kallipolis is the reliance on sensation/sense perception. Brown is not alone in this--in the summary to their translation of book 8, Grube/Reeve assert that kallipolis "will decline because the philosopher-kings have to rely on sense perception in putting their eugenics policy in practice." (213) Let's call this the standard reading. By contrast, the "Straussian" reading has an unhealthy interest in sexual desire.*
And, indeed, the standard reading is well grounded in the text. But the Straussian reading is not silly because what sense perception misses is copulation by the guardians. And what this shows that even a state carefully organized around moderation and properly cultivated dispositions (by way of indoctrination, drilling, censorship, noble lies, and eugenics, etc.) and learning flounders on a mixture of natural drives and cognitive limitations. The standard reading emphasizes these cognitive limitations, whereas the Straussian reading emphasizes the former. The standard reading does justice to the plain meaning of the text. But the Straussian reading is on this point not based on some fancy esoteric numerology+ -- in fact, it's the Socratic eugenicist-philosopher-kings who have to deploy such fancy numerology --, but a fairly straightforward interpretation of why the cognitive limitations induced by sense perception matter.**
So, my objection to the standard reading is not that it is decidedly prudish (although I think that, too, of course), but that it kind of fails to do justice to the very grounds of rejecting the true/healthy city, and to embark on the Kallipolis which is, in part, (recall and more elaborately here) grounded in what's possible for beings like us (the true city assumes we're like pigs/animals). And in analyzing the causes for its decline, it turns out there are limited to improving our human nature (cognitive limitation, sexual desire)* when we are dealing with populations (and population improvement).
As it happens, this week, I am teaching Ibn Rushd's commentary on Plato's Republic (translated from the Hebrew by Ralph Lerner; this Third Treatise 87.20ff.) Here is how he treats the issue in question:
Here the guardians are blamed for the failure of the eugenics problem in two ways: (i) they are not paying sufficient attention to the copulation (of their fellow guardians); (ii) they are not sufficiently ruthless enough in removing or -- to use a term from Al-Farabi -- weeding out the bad offspring that are the product from improper copulation. (Recall that he seems to suggest that Sharia is also offering a breeding program.)
Now, Ibn Rushd's commentary, which presents itself as an epitome that only presents the demonstrable parts of the Republic, here is offering, in one sense, a misleading summary. It's possible that this is due to the manuscript-translation of the Republic he had access to, or to a mistake in the Hebrew translator of Ibn Rushd. But I will assume that the change is deliberate. (There are other places in the commentary where the changes are evidently deliberate.)
Ibn Rushd is frank about the significance of copulation as the proximate cause of decline (so that's like the Straussian). But what (i)-(ii) have in common is that he puts much more emphasis on, we may say, a failure of policy, even a loss of nerve, among the guardians (who are in a sense not ruthless enough in spying and killing, that is, the kind of Straussianism associated, fairly or not, with the neocons). And the underlying sensibility is that, while the best regime is certainly not stable, it is in some sense both more attainable (recall) and also more enduring if one were willing to make one's hands dirty.
*One may say that the Straussian reading is Freudian in so far as it diagnoses the transformation of sexual desire into its opposite (death/destruction). UPDATE: after reflecting on the material, and discussing it with Ruth Groff and Eric Brown on facebook, I now think the Straussian reading is wrong to turn its claim on sexual desire as such. Copulation among the guardians happens for many different sanctioned reasons (honor, reward, and myth following, etc.), and so one can't ascribe the failure of sense perception to a single underlying appetite/drive (especially because eros has so many connotations). What motives/drives produces the wrong copulation is not obvious. The guardians are regulated by institutions and incentives that work on their desire for honor and their fear of shame; among the rewards are access to each other's bodies. So, all my claim needs is that this is not a stable situation.
+Regular readers know (recall) I am no enemy of esoteric readings of texts; I am less receptive to esoteric claims grounded in numerological considerations.
**UPDATE: the standard reading has to claim that there is some kind of mismatch between sensible properties of human bodies and applying the eugenic program. (Artificial selection is difficult, after all.) But what this mismatch involves is left very obscure.