Theories about The Prisoner: Drama vs. Allegory

Why did No 6 resign?

• He found out about the Village, or at least that he was working for the sorts of people who ran the Village. He perceived either that the British secret state - perhaps even the entire British Establishment itself - had become so morally decadent (or had been so subverted) that it was no longer behaving constitutionally. It may even have been infiltrated by a malign agency or agencies unknown. In any event, No 6 felt in conscience he could no longer work for these despotic and amoral "new masters" (quite possibly some sort of X-Files-type shadowy one-world government sort of conspiracy!), so he resigned.
• He did not necessarily know about the Village, but he knew what sorts of things were going on there.
• It's possible that he did already know about the Village in principle, possibly even because he helped to devise it, only late finding out how his plan was actually being implemented - or perhaps, rather, abused.
• He found out that he was No 1 - or at least that his superiors were doing what they were doing at least partly in his name as Britain's number one spy. He no longer wanted to be a leading light in such operations.
• He may even have resigned in the hope of avoiding being sent to the Village (or somewhere like it) himself - though he would probably have been aware of what a vain hope this was. During the scene of his actual abduction, there is more than a hint of Stoic resignation in those blue eyes as he realises he's being gassed. Besides, his "beach holiday" doesn't seem like the sort of holiday he would really have enjoyed (being more of a skiing man), so it's possible that he didn't actually expect to get that far - though it's also possible that the beach holiday really was just an old professional cover he intended to use. (He doesn't actually deny the possibility in A.B.C., merely that he did not intend to "sell out".)
• Patrick McGoohan resigned - from Danger Man. Lew Grade asked him why. Though McGoohan never seems to have said so in so many words, clearly Danger Man was for him too idealised a version of the morally questionable reality of covert surveillance, subversion and guerrilla warfare that all modern governments perpetrate, both internationally and domestically!

Why do the No 2s keep asking No 6 why he resigned?

The original purpose of the Village was simply to protect the data of retired secret agents. If they just wanted to prevent No 6's information from falling into the wrong hands though, the No 2s would simply have killed him, but they didn't. They want to extract the information he has first. In order to do this they will destroy his individuality if necessary (or perhaps even if it's not necessary). In the "allegory" of The Prisoner, according to McGoohan, this was the actual point of the Village - to destroy the individual.

• At first the No 2s think No 6 resigned because he discovered something valuable and they want to know what that was. 
• Later on it becomes clear (e.g. in 'The Chimes of Big Ben') that they hope that if he answers just one simple question (i.e. about his resignation) he'll crack and tell them everything else he knows as well.
• It's also possible that they suspect and fear that he has discovered too much about their own operations - perhaps even the identity of No 1 himself.
• The No 2s themselves almost certainly don't know who No 1 is. This can perhaps be inferred from the evasive answers that many No 2s give about No 1. It is also stated implicitly in 'Hammer into Anvil' and explicitly in 'Fall Out'. In 'Free For All', when No 6 and No 2 are discussing the consequences of being elected No 2, the older man states, 'Number One will no longer be a mystery to you, if you know what I mean.' This sounds like an implicit admission that he doesn't believe there really is a No 1, except in a philosophical sense (e.g. No 1 is some sort of version of God in the Village's quasi-Masonic cult of "government power" - perhaps even Rover himself, which is not impossible, given that Rover is in one sense the supreme symbol of power in the Village. Indeed, at one point at that story's climax No 2's toughs actually seem to be worshipping Rover in some sort of inner sanctum within the Green Dome). For some of the No 2s then, No 1 is a "noble myth", though it's possible that there are others who know that the idea that No 1 is a noble myth is itself a lie. Some of the No 2s may indeed want to know more, so for some of them breaking No 6 to discover whether he knows who No 1 is - or at least whether he knows more about the Village and the powers behind it than they do - is a matter of personal concern to them, as well as of personal honour.
• It's even possible that some of them know (or suspect) that he is No 1 and wish to break him in order to replace him. (This may actually have happened by the time of 'Do Not Forsake Me Oh My Darling' and apparently has happened by the time of 'Fall Out', in which No 1 seems to be No 6's doppelgänger Curtis.)

Who is No 1?

• The original answer (and the only acceptable answer) to 'Who is No 1?' is of course that No 1 is No 6. He is the most important person in the Village, after all, and certainly its most important prisoner. It's not necessarily clear though whether or not he knows that he is No 1.
• The question is of course No 6's equivalent of 'Why did you resign?', the implication being that if he can get them to answer one of his questions then he will have turned the tables on them decisively. 
• He probably either knows the answer or suspects it even as he's asking the question. The difference though is that the No 2s themselves don't know who No 1 is. Whatever they may suspect, they only know that No 6 is important, not that he is No 1.
• It would be most satisfying to imagine that 'Who is No 1?' and 'Why did you resign?' actually have the same answer. Originally the idea was that No 6 had devised the idea of the Village but then resigned when he discovered how/that his idea had been realised. The Prisoner therefore is No 1 and he resigned because he is No 1 and had a change of heart about the Village and what was being done there - or at least he had a change of heart about his job once he realised the sorts of things that were being done by the people he was working for (i.e. the sorts of things that were going on in the Village). Having been the best agent in the service he became its most implacable opponent.
• If he knows that he is No 1 but knows that they don't know, then the question is really little more than a taunt.
• If he knows that he is No 1 and doesn't know that they don't know, then the question is presumably a genuine attempt to discover if any of them knows that he is.
• It's just possible that despite having resigned he, or rather someone posing as him, is still recognised as No 1; and so, in a classic game of bluff and double bluff, whereas the No 2s' objective is to discover whether he realises this, his intention is to discover how it is that the Village continues to function even though he himself is now a prisoner.
• It's just possible that the impostor who has replaced him as No 1 - the figure unmasked by No 6 in 'Fall Out' - is No 6's doppelgänger Curtis, who was not killed by Rover in 'The Schizoid Man' but only stunned. (Does Rover ever actually kill anyone?) It's also possible that Curtis was revived after 'The Schizoid Man' in much the same way as No 2 is in 'Fall Out'. Despite being brain-damaged by his trauma, he was given No 6/the true No 1's place at the "controls" of the Village.
• Implicitly there's not just a No 1. Above and beyond (or, indeed, below) the Village, there's also a No 0 - who is quite possibly the Butler, who still controls No 6 (but more subtly) even after he has left the Village.
• Another good candidate for No 0 is of course Rover - not just the supreme symbol of power in the Village but also the "reset", who returns escapees and thus returns everything to the status quo ante each time they attempt to escape.

Patrick McGoohan, who plays No 6, came up with the idea of the Village based around Portmeirion, which had been one of the locations for Danger Man. According to McGoohan though, No 1 is No 6's self. By implication then, No 1 = No 6, '1' is 'I' and '6' is 'me': one is the self as seen by oneself (the Prisoner himself) and the other is the self as seen by society (the Village). The Prisoner is his own worst enemy because he constantly "looks out for number one". McGoohan also made the point that you can't rebel against society all the time, otherwise you'd go crazy. So No 6 wants to escape from the Village because he rejects society. (He may even deny that there is such a thing as society.) But, as a member of society (i.e. as a number), he cannot escape it, even if he appears to have escaped and,for a time, to have shrugged off its label.

To a certain extent it's necessary to "retroject" this fable's moral onto some episodes, but it works remarkably well. The Prisoner cannot escape the Village because one cannot escape society, and even if one can escape society one cannot truly achieve the individuality of pure subjectivity without either going mad or accepting, to some extent, that one must also be an object of others' actions, observations and labels. One will always be numbered by other people, and even as oneself one must have a number - even if that number is, indeed, 'One'.

It follows though that in all probability each and every individual is No 1, and that anyone else who pulled off No 1's ape mask would see his own face. In as far as he has objective reality, No 1 is a faceless, protean being who represents the dark, utterly selfish, animal side of each man's nature. He can be unmasked and confronted, but he cannot be caught or restrained, let alone imprioned. It's quite likely that he is in charge not only of the Village but also of the world itself: the Village has its nukes, just as the outside world does. As such it it quite likely that he is the Lord of This World that Christ warns of in the Gospels - the Antichrist, Satan himself.

McGoohan: 'I think progress is the biggest enemy on earth, apart from oneself.' 

...  

Audience member: 'Do you think there's going a strong popular reaction against "progress" in the future?' 

McGoohan: 'No!'