ひらく / とじる vs. あける / しめる

Question

The verbs ひらく　and あける both mean to open, and とじる　and しめる both mean to close. I understand that ひらく and とじる are antonym pairs, as are あける and しめる, but have never been clear on the difference between them. I have heard it explained in several different ways, but have come across several cases which seem to refute them. Some of the explanations I have seen are:

1. ひらく/とじる refer to an abstract or figurative opening or closing, such as opening a store, account, or ceremony. あける/しめる are literally opening or closing something (physically).
2. ひらく/とじる are opening or closing something in 3 dimensions (such as a laptop or a car door), where あける/しめる are only used when the opening/closing action only spans one dimension (such as a sliding window or a Japanese style closet).

On the other hand, I have seen buttons on an elevator say ひらく and とじる (which refutes #2). I have never heard ひらく or とじる applied to a door--it's always あける/しめる, whether it's a hinged or a sliding door. I have always heard あける / しめる used when referring to the opening of a store or business (e.g. レストランはあけていますか。). What is the difference between these terms?

And as a secondary question, is ひらく both transitive and intransitive?

Answer 1

I think the key to understanding the differences is to understand the concept of [空間]{くうかん} in Japanese. Basically, if by performing the "open" action, you connect two 空間 together, create a new 空間 or make a 空間 visible, then both ひらく and あける can be used. This can be seen in the following phrases:

窓をあける/ひらく (by opening a window, you connect two 空間 together)

箱をあける/ひらく (by opening a box, you are able to make the inner 空間 of the box visible)

ドアをあける/ひらく (same as window)

目をあける/ひらく (by opening your eyes you make a new 空間 visible)

However, I should stress that generally あける is preferred in the above situations.

Now, let's see some examples that do not fit the above explanation.

本をひらく/あける*

傘をひらく/あける*

羽をひらく/あける*

In the above situations, あける cannot be used. Do you see why? Basically, the concept of 空間 that I mentioned above is missing. What is common about the above examples is that they are more focused on the "movement" of an object. In other words, the cover of the book, the umbrella and wings all move to expand or widen.

From this, we should be able to understand why あける is preferred in my first examples. Since ひらく focuses on "movement" like I explained above, あける should be preferred when focusing on the 空間 aspect.

Also, while the above explains some of the differences, I should note that あける can be written in three ways: 開ける/明ける/空ける, and ひらく has four ways: 開く/拓く/啓く/披く. So, the usage is much more complicated than what I explained above.

For your last question, yes ひらく can be both transitive and intransitive. ひらく and あく are used differently, for example you can say 毛穴がひらく but not 毛穴があく, while 穴があく is better than 穴がひらく.