Sequence of tenses

[Efl_unit]

Hi to all! I have the following text to discuss:

"A young man named Hugo came to the inn and said: 'Tell the boy to meet Miles Hendon at Southwark Bridge', and the boy went away." "That man!" Miles thought. "That man who said that the boy is his son! He sent the young man!"

As I can see it, "Miles thought"- is the past time. The events in its thought take place much earlier than the moment of the thought. So, why the man in Miles' thought "said", but not "had said". Doesn't using the words "said" and "thought" mean referring to the same period of time? The same thing for "He sent the young man"...
But the most confusing thing is why the boy "is his son"... It sounds like that is some generally accepted and known to the world fact, that that boy is a son of "that man".

I would rewrite the last sentence from the quote above as follows:
"That man who had said that the boy been his son! He (had)sent the young man!"

What would you say about it?

[VictorB]

"A young man named Hugo came to the inn and said: 'Tell the boy to meet Miles Hendon at Southwark Bridge', and the boy went away." "That man!" Miles thought. "That man who said that the boy is his son! He sent the young man!"

What would you say about it?

Судя по источнику, откуда этот отрывок (мог быть) взят, я бы сказал, что вопрос высосан из пальца.
Обсуждать грамматику в текстах классиков адаптированных под элементарный уровень владения языком... Какой в этом смысл?
Вот если бы вы привели цитату из оригинального Марка Твена и спросили почему там так, а не иначе .... А пытаться перекроить уже кем-то перекроенное малопродуктивно, IMHO :-)
Да, и на будущее. В 99 случаях из 100 цитаты, положенные в основу ваших вопросов будут гуглиться (что, кстати, я и сделал первым делом) отвечающими, так что лучше все-таки сразу указывать (давать ссылку на) источник этих цитат.
Или, на худой конец, давать более широкий контекст.

[Yety]

The events in his thought take place much earlier than the moment of the thought.

That's true, but the backshift of the Sequence Of Tenses only takes place in the Indirect Speech. You could think about the quotation marks ("") of the Direct Speech as a vaccine that makes the utterance "immune" to the influence of the sequence of tenses. The past form of 'thought' in the story is past for the author and the reader to be perceived as a past action. For Miles, who thinks that, the moment of thinking is obviously present, and the subject matter of his thinking is simply past, innit?:) So, there's no question about Miles' direct words 'said', 'sent' and the author's comment 'thought'.

But the most confusing thing is why the boy "is his son"... It sounds like that is some generally accepted and known to the world fact, that that boy is a son of "that man".

That's one way of putting it.=)
The man said that boy is his son... - the boy was his son then - when he said that, and still is - when his words are reported by Miles. Yep, it's a *generally accepted and known to the world fact*, in a way.
One might as well use the past form, though:

"That man!" Miles thought. "That man who said that the boy WAS his son! He sent the young man!"

Sometimes the sequence of tenses is optional and works even if there's no *logical* reason for it.

[Yety]

Какой в этом смысл?

Есть смысл с оригинальными - так же, как и с адаптированными. Вопросы по грамматике могут быть даже в самых элементарных учебных текстах.

[VictorB]

так же, как и с адаптированными.

Ну да, конечно. Имел в виду, что мне потытка грамматического усложнения адаптированного текста, приводящая к сомнительной грамматичности этого текта показалась...странной. Теперь, когда Yety ответил, беру свои слова про "палец" обратно :)

[VictorB]

the quotation marks ("") of the Direct Speech as a vaccine that makes the utterance "immune" to the influence of the sequence of tenses.

Written in stone!)

[Efl_unit]

Exactly! I didn't pay attention that it's a direct speech... As for is/was... According to the main rules I know at the moment, it isn't quite clear for me that I have to(may) use the preset tense here. The past simple tense is more obvious for me in this case.

Какой в этом смысл?

It's more interesting for me to know how I can use it. Not just how to use, but how to use it in correct ways. If I cannot understand why some thing is written in one or another way, even if it isn't an original text, how I can use it myself?)

[Efl_unit]

By the way. The text indeed is adapted, but positioned as for the intermediate level.

[Yety]

According to the main rules I know at the moment, it isn't quite clear for me that I have to(may) use the preset tense here. The past simple tense is more obvious for me in this case.

Well, you rock-n-roll live-'n'-learn.=)
As I said above, you don't have to use the backshift in the so-called up-to-date reporting.
The backshift is optional here, and the rule is not obligatory. Unlike the case with universal truths or historical facts that resist the backshift at all times.