What's the difference between 「〜を通{とお}して」 and 「〜を通{つう}じて」？

Question

I understand both can mean "by means of, through, throughout", but I'm sure there's a difference in nuance here.

Could someone help explain this?

Answer 1

My grammar book (albeit an older version) says that while many times they can be used interchangeably, を通じて is used when describing the means that brings about some conclusion. Here is the full description from the book:

「～を通じて」「～を通して」は同じように使える場合が多いが、「～を通じて」は「～」を何かが成立するとこの媒介、手段としてとらえ、「～を通して」は「～」を間に立てて何かをする、という積極的な意味で使われることが多い。

Here are some of the example sentences showing that something is concluded by ～を通じて.

• わたしはそのことをテレビのニュースを通じて知りました。
• 彼とは共通の友人を通じて知り合った。
• 「このような民間レベルの国際交流を通じて、両国の相互理解が少しずつでも進んでいくことを願っています。」

And although it does not explicitly say it, I agree that ～を通じて sounds more formal for the interchangeable situations.

Answer 2

The difference between 通す and 通じる:

    
通す -> transitive
(私が)[心臓に]電気を通す
(I will) pass electricity [through the heart].

Transitive means that "X does verb to Y"; が and を are permitted, and に marks any extra participants. in the case of 通す, it means 'X (が) pushes something (を) through Y (に)'. The something (を) may include things like heat, electricity, or even needles.

通じる -> intransitive
(精髄が)[脳に]通じる
(The spinal cord) leads to [the brain]

Intransitive means that "Y does verb"; が and に are permitted. In the case of 通じる, it means 'Y (が) leads to something (に)', or 'Y (が) conveys some meaning (に)'.

Essentially, you are asking what the difference between transitive and intransitive verbs is. Transitivity creates the difference between "I dropped the ball", and "The ball dropped". In both cases, the ball is falling, however, in the first one (transitive), I caused the ball to fall. In the second one (intransitive), the ball just fell... no fanfair, nobody forcing it to fall. Maybe it rolled off a table. Who knows?

The difference between を通して and を通じて

Both the verbs you provided are conjugated into -te form, so in English, they would be used in cases such as the partial sentence "Being a part of the family..." (家族の一員として...). According to this link, they have a similar meaning in that context. The link goes on to say that they are interchangeable. The difference in nuance is likely because を通じて is more formal (a side effect of how indirect intransitive verbs are). According to the link, を通して is naturally used by people, while を通じて is mostly for news and business speech.

Furthermore, the difference between the phrases you gave is very miniscule:

受付を通して、三階に案内された。 
"Going through the reception desk, I was directed to the third floor."
現地の大使館を通じて、外務省に事件の第一報が入った。
"The Ministry of Foreign Affairs received the incident's first report via the local embassy"

Note that the first example may use either. In the second example, however, you would probably sway towards を通じて because it is more formal and indirect (the report passed through the embassy and had to deal with their policies).