Plato’s concept of necessity differs from ours. What is by necessity is without nous or intellect. Necessary causes can act contrary to intelligible causes. What is fixed and unchanging cannot serve as the cause of a world of change, contingency, and chance. It should be noted how often necessity occurs in this story. The various cases helps to give us a better sense of the scope of what necessity means and what it entails — Fooloso4

I don't see where Plato's concept differs from ours. What is needed or must be done by the rulers is intelligible. Human needs are only fixed in as much as nature is fixed. If such needs (biological/erotic) are seen as bad for a city, then rules of law need to be initiated. So, needs cause change.

I didn't notice the frequency of the word 'necessity' as I read Book 10. However, I searched for it in the pdf. of the Republic.
It is mentioned 18 times, including some in the Bibliography and the name of the Goddess Necessity'.

I've just read from Book 5 458d about the breeding programme: the selection of mates. Socrates suggests both females and males are driven (naturally) by 'necessity' to have sex with one another.
He asks Glaucon if he thinks the word 'necessities' is right here. G. says they are not geometric necessities but agrees they are erotic ones.

The discussion turns to how unregulated sexual intercourse would not be a 'pious' thing in a city of happy people. And how to solve this problem by breeding humans in their prime. Mating the best to the best is good. The worst to the worst is bad. The offspring of the best to be taken away and reared by special nurses in a separate part of the city. The inferior or disabled will hide in a secret, unknown place.

All of this can only be achieved by subterfuge by the rulers. The 'drugs' of lies and deception by lottery.
All to keep the race of guardians pure.

Just as MU says:

...there is really intelligence behind the scene which creates the appearance of random chance for all those being selected from, and only a distinct class of people are privy to that information. — Metaphysician Undercover

619d He was one of those who had come down from heaven, having lived his previous life in an orderly constitution, sharing in virtue through habit but without philosophy.
Generally speaking, not the least number of the people caught out in this way were souls who came from heaven, and so were untrained in sufferings. The majority of those from the earth, on the other hand, because they had suffered themselves and had seen others doing so, were in no rush to make their choices.

This does not make sense to me. If people were in heaven, then they will already have been judged as good. Even if their virtue is through habit, it is part of their character, formed and informed by life experience and doesn't mean 'without philosophy'.
There is an assumption that they are 'untrained in sufferings'.
However, Life and others within are the trainers. No academic philosophers required. In fact, arguably, they are the least qualified.

Unlike most souls who made their choice based upon the habits of the previous life, (620a) Odysseus now chooses a life of moderation. The suggestion seems to be that although he has chosen last he is an example of someone who has attained phronesis, someone who engaged in philosophy, consistently, in a sound manner. — Fooloso4

I am not sure this is correct. Choices were made by those from heaven. Of different character and ways of thinking. Odysseus' soul made its choice, not because of unthinking habit but:

Remembering its former sufferings, it rejected love of honor, and went around for a long time looking for the life of a private individual who did his own work, and with difficulty it found one lying offsomewhere neglected by the others. When it saw it, it said that it would have done the same even if it had drawn the first-place lot, and chose it gladly.

620d.

This is a set-up to enhance the virtues of philosophy. There seems to be an assumption that the ordinary individual will not be troubled by sufferings or thoughts of being honourable. What kind of love would the ordinary person have? And how would it be regulated...if necessity or rulers required...

I believe we can take modern usage of "necessity", and divide it into two principal categories. We have on the one hand, what is said to be "necessary" as determined by the physical forces of the universe, or the laws of nature. This is the sense which is at the base of determinism. On the other hand we have what is "necessary" as determined by the needs of a free willing being. This is the sense when people desire something as the means to an end, it is needed for that purpose.

We can see, that in much of common, modern usage, it is usually not hard to distinguish the two, it's a pretty straight forward analysis which is required to make that judgement. However, then we have a type of necessity which can be understood as "logical necessity". This is what forces logical conclusions. A thorough analysis will show that this sense of "necessity" is really a subdivision of the sense which is based in the needs of a free willing being, "the means to an end". However, many people will not accept this designation, wanting to assign "logical necessity" more force, making it closer to the sense of "necessity" which is at the base of determinism. However, they generally find that it doesn't quite qualify as a determinist "necessity" because it cannot be shown to be driven by the laws of nature. So they propose another distinct sense of "necessity", a third principal type.

The acceptance of this third type of "necessity" produces a lot of confusion, making the judgement of a specific instance of usage much more difficult. Instead of seeing logic as the means to an end, we now have to distinguish the use of logic as distinct from other decision making practises, to place it in a distinct category which some want to portray as closer to being "necessity" in the sense of being driven by the laws of nature than to being "the means to an end". Furthermore, since decision making generally involves some form of logic, it pulls the whole model of "choice" away from the "means to an end" portrayal toward the determinist portrayal.

In reality, a complete and very thorough analysis of "the concept", "necessity", shows that the opposite is what is the case. The "necessity" of determinism is just a special type of "logical necessity", which is a special type of "means to an end" type of "necessity".

We can see, that in Plato's day these distinctions were even less clear than they are today. The concept "|necessity" was young and underdeveloped. But we have to keep in mind, that since the "means to an end" sense is the overarching sense, it is the other sense, the highly specialized determinist sense of "necessary by the laws of nature" which is not yet developed at Plato's time. It is portrayed as "fate". So we see a recognizable representation of "the means to an end" sense of necessity, but the determinist "laws of nature" sense is not well portrayed at all. It is presented as "a lottery". What we call "the laws of nature" present us with one's "lot in life", the circumstances of one's being, and this is presented by Plato as random chance, with some sort of "necessity" lurking beneath it, which drives it. That sense of "necessity" is some how comparable, or related to the "necessity" which is "the means to an end", but the relation is not really intelligible to those people involved in that discussion because they have a primitive understanding about the laws of nature and determinist forces.

What we call "the laws of nature" present us with one's "lot in life", the circumstances of one's being, and this is presented by Plato as random chance, with some sort of "necessity" lurking beneath it, which drives it. That sense of "necessity" is some how comparable, or related to the "necessity" which is "the means to an end", but the relation is not really intelligible to those people involved in that discussion because they have a primitive understanding about the laws of nature and determinist forces. — Metaphysician Undercover

[emphasis added]

Thank you for your post. Interesting to consider. The understanding of the Cosmos. How it was made intelligible by Plato.
As far as possible.

In the eponymous dialogue Timaeus he identifies two kinds of cause, intelligence and necessity, that is, Nous and Ananke. Given the earlier emphasis in the Republic on the Forms, the introduction of ananke is both surprising and significant. Here at the end we must, by necessity, begin again. Forms and their imperfect images do not tell the whole of the story. — Fooloso4

Checking out the Timaeus, I think I begin to understand:

In the Timaeus Plato presents an elaborately wrought account of the formation of the universe and an explanation of its impressive order and beauty.

The universe, he proposes, is the product of rational, purposive, and beneficent agency. It is the handiwork of a divine Craftsman (“Demiurge,” dêmiourgos, 28a6) who, imitating an unchanging and eternal model, imposes mathematical order on a preexistent chaos to generate the ordered universe (kosmos).

The governing explanatory principle of the account is teleological: the universe as a whole as well as its various parts are so arranged as to produce a vast array of good effects. For Plato this arrangement is not fortuitous, but the outcome of the deliberate intent of Intellect (nous), anthropomorphically represented by the figure of the Craftsman who plans and constructs a world that is as excellent as its nature permits it to be. — SEP - Plato's Timaeus

[ emphasis added]

So, not random but deliberate. 'Necessity' driving it. We might not be convinced by the story of a divinely created universe. However, there is no doubting the force of Plato's imaginative description. How we can enter into it; admire the images and probe its concepts. The process of philosophy is well on its way. Just what he wanted or needed. Intellect and imagination working together in dialogue.
Philosophy and poetry dancing...as one.

Plato’s concept of necessity differs from ours. What is by necessity is without nous or intellect. Necessary causes can act contrary to intelligible causes. — Fooloso4

I wonder if the language of Hesiod plays a part in this:

Thus it is not possible to deceive or elude the mind of Zeus. For not even Iapetus’ son, guileful34 Prometheus, escaped his heavy wrath, but by necessity a great bond holds him down, shrewd though he be. — Hesiod, Theogony, 613, translated by Glenn W. Most

Each soul chooses a daimon and also a pattern of life. (617e) The daimon is the guardian of that life. (620d) Nothing is said about choosing a daimon, on what basis it is chosen, or how closely it reflects the soul that chooses it. — Fooloso4

The relationship between the choosing and the daimon seems to be an assignment by a daughter of Necessity:

“So when all the souls had chosen their lives, according to the draw they approached Lachesis in order and she gave each the spirit (daimon) they had chosen to escort them as protector through their lives and as fulfiller of their choices. — ibid. 620d

The daimon impels a movement forward as well as enforcing the consequences of the choice.

Comparing the myth of Er with Hesiod's Theogony, shows the Fates literally having a darker story in the latter version:

Night bore loathsome Doom and black Fate and Death, and she bore Sleep, and she gave birth to the tribe of Dreams. Second, then, gloomy Night bore Blame and painful Distress, although she had slept with none of the gods, and the Hesperides, who care for the golden, beautiful apples beyond glorious Ocean and the trees bearing this fruit. And she bore (a) Destinies and (b) pitilessly punishing Fates, (a) Clotho (Spinner) and Lachesis (Portion) and Atropos (Inflexible), who give to mortals when they are born both good and evil to have, and (b) who hold fast to the transgressions of both men and gods; and the goddesses never cease from their terrible wrath until they give evil punishment to whoever commits a crime. Deadly Night gave birth to Nemesis (Indignation) too, a woe for mortal human beings; and after her she bore Deceit and Fondness and baneful Old Age, and she bore hard-hearted Strife. — ibid. 211

The role of the daimon emerges as a dynamic belonging to an individual life.

I don't see where Plato's concept differs from ours. — Amity

In the Timaeus necessity is called the wandering or errant cause. (48a) The necessary connection between necessity (ananke) and chance (tyke) is discussed in Plato’s Laws:

Fire, water, earth and air all exist by nature and chance, they say, and none of these exist by artifice. And the bodies that then come after these, those of the earth, sun, moon and stars, have come into being through these four, entirely soulless entities. They move by chance, each according to its particular power, in such a way that they come together, combining somehow with their own, hot with cold, dry with moist, soft with hard and so on for any mixture of opposites that is produced, of necessity, according to chance. In this way, based upon these processes the whole heaven has come into existence and everything under heaven, including animals and indeed all the plants too, and from these all the seasons have arisen, not through intelligence, they say, or through the agency of a god, or through artifice, but, according to them, through nature and chance.

(889b-c) Emphasis added.

The relationship between the choosing and the daimon seems to be an assignment by a daughter of Necessity:

“So when all the souls had chosen their lives, according to the draw they approached Lachesis in order and she gave each the spirit (daimon) they had chosen to escort them as protector through their lives and as fulfiller of their choices.
— ibid. 620d — Paine

Thanks. Following the process has not been easy for me. I confused the 'soul' with the new life and then the choosing of a new 'spirit' (daimon). Soul and life seem to be used interchangeably.
- see underlined bolds below.

I didn't understand the daimon 's role or how the spindle of Necessity fitted in. Also, missed the prophet as intermediary.

From Reeve's translation, 617d:

When the souls arrived, they had to go straight to Lachesis. A sort of spokesman 29 first arranged them in ranks; then, taking lots and models of lives from the lap of Lachesis, he mounted a high platform, and said:
“The word of Lachesis, maiden daughter of Necessity! Ephemeral souls. The beginning of another death-bringing cycle for mortal-kind! Your daimon will not be assigned to you by lot; you will choose him.
The one who has the first lot will be the first to choose a life to which he will be bound by necessity.
Virtue has no master: as he honors or dishonors it, so shall each of you have more or less of it. Responsibility lies with the chooser; the god is blameless.”

After saying that, the spokesman threw the lots out among them all, and each picked up the one that fell next to him—except for Er, who was not allowed. And to the one who picked it up, it was clear what number he had drawn. After that again the spokesman placed the models of lives on the
ground before them—many more of them than those who were present.

Note 29: Prophêtês: a prophet. Here in the sense of someone who speaks on behalf of a god.

[emphasis added]
I don't quite understand what is being said here of Virtue. However, this might relate to my earlier confusion: https://thephilosophyforum.com/discussion/comment/939791

620d When all the souls had chosen lives, in the same allotted order they went forward to Lachesis. She assigned to each the daimon it had chosen, as guardian of its life and fulfiller of its choices. This daimon first led the soul under the hand of Clotho as it turned the revolving spindle, thus ratifying the allotted fate it had chosen.
After receiving her touch, he led the soul to the spinning of Atropos, to make the spun fate irreversible. Then, without turning around, it went under the throne of Necessity. When it had passed through that, and when the others had also passed through, they all traveled to the plain of Lethe, through burning and choking and terrible heat, for it was empty of trees and earthly vegetation. — As above

[emphasis added]

I need to put the theory of reading slowly and carefully into practice. Especially here.
Even then, I welcome insight, clarification and advice from those more experienced with Plato.

Thank you for further explanation from places other than Book10.

This does not make sense to me. If people were in heaven, then they will already have been judged as good. Even if their virtue is through habit, it is part of their character, formed and informed by life experience and doesn't mean 'without philosophy'. — Amity

One can be brought up with good habits, but that does not mean that philosophy is part of their education. Good habits do not preclude philosophy, but may not be the result of philosophy.

'untrained in sufferings' — Amity

Perhaps given their wealth and good fortune Cephalus and Polemarchus are untrained in suffering. Socrates repeats a common assumption to Cephalus:

... for they say that wealthy people have consolation in abundance.

(329e)

Cephalus agrees and goes on to say:

Indeed, the possession of wealth has a major role to play in ensuring that one does not cheat or deceive someone intentionally ...

(331b)

No academic philosophers required. — Amity

I agree. As I understand it, what is meant by philosophy here is something different. I will have more to say on this in connection to the River of Forgetfulness.

Yes, the choice of the soul does seem to be separated from the work of assignment by Lachesis.

I am not sure how it relates to your previous comment about virtue, but I read the role of 'assignment' in this passage as meaning that much more is required for our life to happen than the initial choice. Those requirements, however, do not allow us to "blame the gods" for our choice.

I read the role of 'assignment' in this passage as meaning that much more is required for our life to happen than the initial choice. Those requirements, however, do not allow us to "blame the gods" for our choice. — Paine

:up: That makes sense.

As I understand it, what is meant by philosophy here is something different. I will have more to say on this in connection to the River of Forgetfulness. — Fooloso4

OK. :up:

I took Lachesis' role to be that once the choice of a daimon and of a life is made by the soul, that choice becomes part of the fate of that soul. There is a connection here with something Socrates tells his friends in the Phaedo:

... all who actually engage in philosophy aright are practising nothing other than dying and being dead.

(64a)

The best preparation for making that fateful choice is something you can do now.

With regard to virtue or excellence, it too is a choice:

... each will have more of her or less of her, as he honours her or dishonours her.

(617e)

I agree with that interpretation. I also agree with your view of Odysseus as a 'repurposed' life.

The distinction between the choice and the "assignment" of fate also has the cosmological dimension of depicting the life we encounter. Just as the Timaeus does in your comment here.

Edited to add @Fooloso4:
The cosmological element is also what I was thinking about above when comparing the three daughters as depicted in Er and in Theogony. Like Homer, Hesiod is preserved and changed at the same time.

Looking back I see that I did not include quotation marks for the passage from the Laws. I have edited it.