came to the / a conclusion that

English as a Second Language English Vocabulary, Grammar and Idioms
1

I’d appreciate it if someone would answer my question about the following 2 sentences. Thank you in advance.

A: They came to the conclusion that humans were born to be free.

B: They came to the conclusion that they had to abandon the plan.

I’d like to know the reason “the” is added to “conclusion” in both sentences.

I think the reason in A is that people at large know or think humans are born to be free, and so is the listener of A. The listener can specify the conclusion. Am I right?

I have 2 explanations for the reason in B. One is that the listener know them and their plan, so he/she can specify the conclusion.
The other is that the word “conclusion” has a strong power to restrict, and is easily specified, regardless of the listener’s knowledge of them and their plan, by “that they had to abandon the plan”.
Which explanation is correct, or neither, or some other one?

By the way is C OK?

C: They came to a conclusion that they had to abandon the plan.

3

When the conclusion is known and specific, the use of ‘the’ is justified.

Look at this: They should come to a conclusion (as to) whether or not to abandon the plan. (Here the conclusion is not known and specific as you can see)

4

Thank you Anglophile. I see your idea very well. But there is one thing I’m not so sure. Generally “conclusion” is preceded by some kind of thought or discussion. Considering the situation of B, there had to be a talk or discussion about the plan before the conclusion, and it’s possible the listener knew the talk or discussion or the plan.
The same can be said with “result”. I’ d like your opinion.

5

If the listener knows that one particular suggestion, out of the many that were mooted during the discussion, is going to be accepted, the use of ‘the’ is okay.

The purpose of communication is to convey our thoughts in an unambiguous manner. When what we say is clear to the listener or the reader, communication is complete.

6

Thank you Anglophile.