A quote from 星の王子様 (The Little Prince)


There is a popular quote from the famous novel _The Little Prince_ :

> What is essential is invisible to the eye.

The Japanese translation goes something like this:

> 大切な物は目に見えないんだ。

I have three questions: First, invisible is "cannot be seen". Why is 見えない used
instead of 見られない？

Second, what does it mean when you put: んだ in the end of the sentence? For me
i wouldnt have thought about it and could have ended with みられない。

Third, 大切 is important. Since the word used in the text is essential, is it
possible that there is a better word for that? Something that is one level
higher than just being important? Perhaps a level like 欠かせない。




**Q1** : Because the verb 見える has [more than one
meaning](http://dictionary.goo.ne.jp/jn/210883/meaning/m0u/), and it can both
mean "to be able to see (something)" and "to be visible". See [this
question](https://japanese.stackexchange.com/q/21516/5010), too.

**Q2** : んだ is a colloquial form of のだ. See [this
question](https://japanese.stackexchange.com/q/23936/5010).

**Q3** : Literally, _important_ is 大切/重要 and _essential_ is 本質的. And according
to [this page](http://ijustat.com/gaikokugo/le_petit_prince/01.html), the
original French version seems to contain two similar sentences, one using
_essentiel_ and one using _important_ :

>   * **L'essentiel** est invisible pour les yeux.
>   * Le plus **important** est invisible.
>

The translation of the latter using _important_ seems to be better-known in
Japan. 「本質的なものは目に見えない」 would perfectly make sense, but the word 本質的 may be a
bit too difficult for children.




**Q1** : Because the verb 見える has [more than one
meaning](http://dictionary.goo.ne.jp/jn/210883/meaning/m0u/), and it can both
mean "to be able to see (something)" and "to be visible". See [this
question](https://japanese.stackexchange.com/q/21516/5010), too.

**Q2** : んだ is a colloquial form of のだ. See [this
question](https://japanese.stackexchange.com/q/23936/5010).

**Q3** : Literally, _important_ is 大切/重要 and _essential_ is 本質的. And according
to [this page](http://ijustat.com/gaikokugo/le_petit_prince/01.html), the
original French version seems to contain two similar sentences, one using
_essentiel_ and one using _important_ :

>   * **L'essentiel** est invisible pour les yeux.
>   * Le plus **important** est invisible.
>

The translation of the latter using _important_ seems to be better-known in
Japan. 「本質的なものは目に見えない」 would perfectly make sense, but the word 本質的 may be a
bit too difficult for children.

