grammar - Difference between 六歳にして and 六歳で

というわけで、僕は六歳にして、画家というすばらしい職業をめざすのをあきらめた。
For that reason, at six years old I abandoned my goal of having a wonderful occupation as a painter.

I don't really understand how にして works here. Literally I read "making into six years old". So might "having reached six years old" be a better translation than "at six years old"?

Answer

There is quite a big (and important) difference in meaning and nuance between 「六歳{ろくさい}で」 and 「六歳にして」.

「六歳で」 is just neutral and factual. "One did something at age six." There is no surprise or any other special feeling expressed regarding it happening at that age. For instance, if you moved to London with your family or started learning to play the piano when you were six, that would be 「六歳で」. No one would wonder "Why so early/late?", would he?

「六歳で」, therefore, is synonymous to 「六歳の時{とき}に」.

「六歳にして」 is much different in that it expresses the speaker's feeling that it was (a little) too early for something to occur at age six. Thus, it would mean "at as young as (six)", "at a rather young age of (six)", etc. One would normally expect that to happen at a later stage in life (if it happened).

"For that reason, at a rather young age of six, I abandoned my goal of having a wonderful occupation as a painter."

I am afraid neither "making into six years old" nor "having reached six years old" would capture the nuance of the phrase. The former does not even make much sense (to me at least).