What's the meaning of 〜というものではない？

Question

I have two textbooks, and they seem to give opposite definitions for 「〜というものではない」. The first one says it means "it's not just a matter"; while the other one says that

[It follows] a statement to express that the speaker really feels the statement to be accurate or appropriate. [It emphasizes] the speaker's desire to convey the meaning of the statement or the essence of the matter discussed.

My confusion manifests in the following example sentences, which appear to have almost opposite meanings given each explanation:

• この病気は寝ていれば治るというものではない。
• 相手が好きだから結婚できるというものでもない。

From what I understand, I would translate them either (using the first explanation) as

• Curing this disease isn't just a matter of resting in bed.
• You cannot marry your partner just because you love him/her.

or (using the other explanation) as

• I really think that resting in bed will cure you of this disease.
• I really think that you can marry your partner because you love him/her.

Can someone fill me in on the points I'm obviously missing? Thank you.

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Edit: I checked with my teacher; and she agrees with the two answers below. Thanks again!

Answer 1

The first explanation is correct, that is to say the appropriate translations for your examples would be:

• Curing this disease isn't just a matter of resting in bed.
• You cannot marry your partner just because you love him/her.

Another example:

• どんなことでもお金で解決できるというものではない。 It's not always possible to resolve any problem with money.

Now I somewhat agree with your second manual, in that it brings some emphasis. But not to the statement preceding 〜というものではない, it would be to the whole sentence. It would be interesting if this (second) manual included some examples...

Answer 2

I think you're trying to give a positive meaning to the second explanation. The expression does add an extra air of confidence, but it is still ultimately a negative construction. The two explanations boil down to the same general meaning, but the second one you give just doesn't explicitly say that it's a negative. That should be apparent from looking at the actual construction itself and thinking about what it's saying.

For example, you gave:

この病気は寝ていれば治るというものではない。

The important part is ものではない. It's saying that it's not whatever sort of thing is being described, in this case an illness that will be cured just by sleeping. There's no way you can look at it grammatically from the Japanese and arrive at the conclusion that it is making some sort of positive statement, i.e. that it is definitely an illness that will be cured by sleeping.

In English saying "it's not just a matter of~" is a way of asserting a rather strong opinion about a way of doing something, and the second explanation is saying it more directly, but you have to be careful of the overall negative-ness of the grammar itself.