Interest in the Socratic / Platonic question rekindled after reading the first section of Lloyd Gerson's Plato and Platonism. Ends up re-reading quite a bit of Catherine Zuckert's work, which led me to bought a second-hand Debra Nail's The People of Plato, which I read maybe half before the book disappeared, after a library tour browsing through new books on Socrates and Plato that came out after Zuckert's book. Quite strange.
The Platonic Corpus, completely translated into English in John Cooper's edition, includes 45 separate works, if we lump all Letters as one work, and all Epigrams as one Work. This Corpus requires classification, which has been done many times since antiquity, at least for the very basic reason that there are just a lot of materials to handle. And Plato being almost always included in any list of canonical texts - putting in some efforts seem worthwhile.
Zuckert's basic premise is she accepts the tradition classification of 9 tetralogies; that is the list of 36 works including the Letters. And she reads it in dramatic chronology - that is, when the dialogue main actions / discussions was supposed to have taken place, according to what was written down by the author.
This is clearly refreshing after generations of students get increasingly confused by the Early / Middle / Late dialogues from the "Developmentalist" paradigm. While I am overall sympathetic, I can't say I completely agree with Zuckert's take.
My main issue I have is that there are some dialogues in the tetralogies that just do not allow dating - e.g. Philebus. Some have dates that are very implicit and hard to pin down, e.g. Republic, Gorgias. One even has probably deliberate anachronisms (Menexenus). So how could the author (Plato or pseudo-Platos) intend all the dialogues are read according to the dramatic chronology?
I do agree that the dialogues give explicit hints about how the dialogues should be read together. But I argue that the author(s) of the dialogues would gesture this in somewhat more explicit ways - e.g. hint in the upfront frame, or put the hint very near the end of the work, or in the form of who are chosen as the interlocutors, titles? etc. That is, those hints need to be "explicit" enough such that it wouldn't take generations of scholars to debate and discover.
The second, less important issue I have is that as a reading order, starting with the Laws (as the work with only pre-socratic background) is really really too intimidating for any student. At best it is a pre-quel that can be read after most of the other works in the corpus are digested.
As such, if I accept the 9 tetralogies as the scope to classify works, in some sort of reading orders, I would classify into 4 "octalogies" plus a tetralogy as an "appendix"
Group I - Last year of Socrates, Trial and Death. This is same as Zuckert's grouping. This group of works have relative dating quite explicit and clear. Only exception is Cratylus - but with its multiple reference to Euthyphro (who is probably not a well known figure by the time Plato wrote his dialogues), I think putting Cratylus here is more convincing than Debra Nails' argument that Socrates might have talked to Euthyphro multiple times.
Works (in reading order): Apology, Crito, Phaedo, Euthyphro, Cratylus, Theaetetus, Sophist, Statesmen
This reading order starts with Socrates' defence, how he does not escape, and last teachings and death. Very good starting point to the Corpus. Euthyphro / Cratylus happened on the day after Theaetetus, but Theaetetus/Sophist/Statesmen forms an explicit trilogy. If the starting point is the last phrase of Socrates, then the reading order going broadly backward in time makes sense. The way I order it put Theaetetus as a work that happens on the day of Theaetetus-Euthyphro-Cratylus, but also as beginning of the Theaetetus-Sophist-Statesman trilogy. Because this 8 works is clearly a group (happens to be the first 2 tetralogies), this also establish 8 works as a convenient number for grouping.
Group II - Last decade of Socrates / as Plato knew Socrates. This is a modification of Zuckert's - in a) I think the last decade of Socrates more or less coincides with the period when Plato probably knew Socrates in person (according to Debra Nails Plato probably was born 424/423BC). b) I feel Gorgias, who is well known to have visited Athens in 427BC, should not belong here even though there might be anachronisms that suggest a later date.
II-A (in order): Theages, Euthydemus, Lysis, Meno
II-B (not yet in order): Minos, Hipparchus, Rival Lovers, Philebus
For II-A: those are not necessarily explicitly dated, but are datable. Meno has Anytus (Socrates' accuser) appearing; Crito/Critobulus (key folks in Group I) were speakers in Euthydemus, which is linked to Lysis through Ctesippus. (I am not sure I have a strong view as to whether Euthydemus or Lysis is the earlier dialogue; Nail and Zuckert feel differently). Theages I believe is also mentioned in the Apology or Phaedo - so even without explicit dating, the interlocutors of the dialogues gesture quite clearly that it is Socrates' late teachings (though not in his last year). Also notice that the title characters include Socrates' associate (Theages), sophist (Ethydemus), rich youth (Lysis), Meno (foreign public figure). These can be tied to what was said in Apology.
For II-B: I think the fact that these are explicitly not datable; interlocutors unidentified (or in case of Philebus, made up names) clearly put them in one group. When should these be read in what order? I tentatively put here, but subject to further thinking and debate
Group III - Imagined debates between Socrates and poets, politicians and philosophers. The datings of this group is not always clear, but the impression of these being in Socrates' prime years (except for Parmenides) during the second part of the Peloponnesian war. Plato was just a boy, and some of these dialogues, it was gestured that Plato learnt some of these from his brothers (Adeimantus and Glaucon). Given the length of many of these discussions, I don't feel like the author(s) necessarily want readers to believe all these are conversations that really has happened.
III (tentative order): Parmenides, Symposium, Phaedrus, Ion, Clitophon, Republic, Timaeus, Critias
This is mostly Zuckert's list, just switching in Parmenides as Philebus as a clearly undated dialogue I feel fit elsewhere. Parmenides' main action is early, but the frame refers to Plato's brothers who are also featured in Republic - so Parmenides fit in this group.
Group IV - Socrates' early career. Most happen before Plato can witness and comprehend when took place, some when Plato was not even born. This is again mostly Zuckert's list with just Gorgias added.
IV - Protagoras, Alcibiades I, II, Charmides, Gorgias, Laches, Hippias Major, Minor
Now this can be grouped in two sub-tetralogies: following Zuckert by time, the above 8 could be just cut in half for each sub-tetralogy. Personally I favor another way, which is to split this with protagonist:
IV-A: Protagoras, Gorgias, Hippias Major, Minor -- these are sophists
IV-B: Alcibiades I, II, Charmides, Laches -- these are Athenian youths / citizens
Reading in these group of 4 "octalogies", it starts with Socrates' speech & actions, and also ends that way. Socrates' philosophy is open-ended (always debatable - if it is already a closed book, there is no need for Academy), but the fact that he acts well should never be in doubt, according to the Platonic Corpus.
Appendix Tetralogy: Prequels/Epilogues.
Appendix: Laws, Epinomis, Menexenus, Letters
Laws and Epinomis do not even figure Socrates - so clearly Appendix materials. Zuckert's interpretation these are all pre-socratic theory is quite interesting - making these the prequels to the Socratic dialogues. Menexenus has Socrate's speaking a funeral oration from the grave. Letters is supposed to tell readers something about what Plato himself thinks.
This small exercise is really trying to rethink Zuckert in guiding a reading direction. If I were to pursue more in-depth study of the Platonic Corpus, I would need to:
A) Decide the status of Group III dialogues - especially whether Plato think any of these people like Parmenides, Timaeus, Critias, or the other speakers in Symposiums - are they speaking Plato's views?? Zuckert believes no. This is a key interpretive move, and I feel I can only get to my own view after studying group I works, especially Sophist and Statesman. If from these two it is clear the views are not really sponsored by Plato reading them in context of Apology through Phaedo, then Zuckert's view becomes much easier to accept.
B) II-B - is there a point to these undated dialogues? Does reading these together throws new light on Philebus?
C) My inclination now is to try to interpret the dialogues as extended "Apology". This intuition is further reinforced after I read that Anthony Long (in his 1998 work on Theaetetus, "Plato's Apologies and Socrates in the Theaetetus" in Method in Ancient Philosophy, I found the reference from Zina's Giannopoulou's book Plato's Theaetetus as a Second Apology) has wrote something to the effect that Plato never stops rewriting the Apology. I think there is something to be said about this interpretation, which comes naturally if the reading order starts from Apology as I suggest here.