Someone might say: If the existence of this city [kallipolis] can only come about if people such as these happen to exist, and their existing with these qualities [is contingent on] their having grown up in this city, why then there is no way in this city can come into being. What we were laying down in speech and had then thought to be possible is [now seen to be] impossible.--Ibn Rushd Commentary on Plato's Republic, Treatise 2, 62.24, translated by Ralph Lerner.
The toughest version of the the transition problem (recall and here) is how to create an ideal political future with a population raised under bad institutions (or worse, that is, bad breeding). One of the central philosophical tasks according to Socrates (recall my treatment of Republic 592ab) is the ongoing theoretical exploration of ideal models of political orders that are humanly possible (in the sense of not violating known human nature), but de facto unavailable given the near-impossibility of solving the transition problem.
In his commentary, Ibn Rushd articulates the transition problem very nicely, but skips the paragraph (Rep 592) in which Socrates acknowledges it.* In particular, he offers his own distinctive, solution to it. This has three features. First, and here he echoes a commitment expressed by Socrates, he allows that would-be-philosophical legislators can originate under bad circumstances (62.27). Philosophies can be cultivated, but they can also be natural flukes born anywhere.
Second, such a would-be-philosophical-legislator has pre-existing materials, including (a) not what he calls the "general common nomos;" it is not entirely clear what he means by this, but in a note, the translator, Lerner ,plausibly suggests it is a kind of natural standard for any human association. This standard is something short of natural law, but more the kind of thing that regulates (to use a phrase of Adam Smith) "the usual strain" of in-group relations. In addition, (b) would-be legislators may be able to work with, and adapt pre-existing religious laws. This, too, fits with an import commitment of Socrates, which presupposes (recall) at the founding of the Kallipolis, a rationalized version of existing religious practices and theology (see Republic 427bc & 469a). For, (c) the pre-existing religious laws partake in some sense of the rational order that is achieved (were the transition problem solved.) Rather than seeing religion as opposed to rational political order, it is a natural stepping stone to it. (This fits in with the larger, Platonizing tendency (recall Al-Farabi) to treat religion as a politically functional, symbolic representation of the truth and indicative of the truth/rational order.)
Strikingly, Ibn Rushd explicitly asserts that these pre-conditions exist in his own time and in Sharia. I call this striking because he is also extremely critical of the political conditions and (religious) intellectuals of his time. One may understand Ibn Rushd's Decisive Treatise as the work that explains how such rationalized religion is possible within Islam.
Third, he suggests that one can build the conditions for the emergence of Kallipolis over time, when "virtuous kings" come to rule in succession, "one after another and for a long time--not ceasing to incline these cities gradually until the situation in them, by the end of time, comes to be good governance." (Again, "these cities" refer to the political situation of his own time.) Here Ibn Rushd reverses a template that is familiar both from Al-Farabi and the history of early Islam, in which a succession of second best, but good kings preserves a perfect founding absent a philosopher-king; but he uses the possibility of such a series of second bests, as a a gradual ascent toward the best city.
Such second-best good kings, must nudge the polity toward dispositions that facilitate good beliefs and virtuous deeds simultaneously. Ibn Rushd assumes here that it is possible that political rulers are capable and willing of seeing their own rule as part of a larger architecture or plan. This is is not silly because plenty of rulers (can) understand themselves in terms of dynastic or national interests; religiously inspired rulers do not find it difficult to understand their temporary rule in terms of a providential plan/order. (Ibn Rushd is quiet to what degree such rulers would have to share their long-term plan with their subjects.) Scientists today routinely understand their own work and contributions in terms of open-ended projects that will outlive them.
The starting points of such a multi-generational political project differs in space and time. So, for example, Ibn Rushd is explicit that in his own time the inclination toward virtuous deeds is "more likely than their inclining to good beliefs," (79.5; as noted above he is very critical of the intellectual atmosphere of his own era).
One may think that a multi-generational, top-down political project carried by a cognitive elite, and centered on their decision-making, on behalf of a very idealistic ideals is an outlandish possibility. (In response, Ibn Khaldun will argue that dynasties have natural cycles of rise and fall.) That such a proposal this does not really address the transition problem. But it is worth reminding ourselves that inspired by (recall Kant's Perpetual Peace (who drew on a more dismal picture of human nature), the European Union has been engaged in such a project. And while it is quite possible that we will witness the collapse of it in the near future, it also also possible that it will sustain itself. The comparison with the EU is a bit fanciful, but Ibn Rushd could count on his readers to imagine such a multi-generational political project in terms of a caliphate.