What is the difference in nuance between 思ったら and 思えたら?


敷島の日本の国に人二人有りとし思はば何か歎かむ is always translated into modern Japanese as some
variation of 大和の国にあなたが二人いると思えたら何かを嘆こう and I'm wondering why is 思はば translated
as 思えたら. Why not 思ったら? -aば is the conditional form right? What's the
difference?




You are correct that 思はば in classical Japanese is basically a plain
conditional ("if I think"). However, in this context, it has a mood of
**counterfactual** assumption ("if I were to think...", "if only I could
think..."). The author was in despair because there was only one あなた in
reality. The Japanese language does not have a direct equivalent of
[counterfactual
subjunctive](https://en.wikipedia.org/wiki/Counterfactual_conditional) in
English, and the simplest way to explicitly express this counterfactual mood
in modern Japanese is 思えたら or 思えるなら. あなたが二人いると思ったら without のに would sound like
the author actually started to believe there is another あなた ("now that I think
there are two _anata_...").

This 何か歎かむ is a rhetorical question ("what will I grieve about?" → "I won't
grieve about anything"), so its modern literal translation should be 何を嘆こう,
not 何 **か** を嘆こう.

**EDIT:** I think it's possible to use 思ったら in combination with のに to
translate this waka into modern Japanese (あなたが二人いると思ったら何も嘆かない(でいい) **のに** ),
but then the rhetorical question part would have to be less literal.




You are correct that 思はば in classical Japanese is basically a plain
conditional ("if I think"). However, in this context, it has a mood of
**counterfactual** assumption ("if I were to think...", "if only I could
think..."). The author was in despair because there was only one あなた in
reality. The Japanese language does not have a direct equivalent of
[counterfactual
subjunctive](https://en.wikipedia.org/wiki/Counterfactual_conditional) in
English, and the simplest way to explicitly express this counterfactual mood
in modern Japanese is 思えたら or 思えるなら. あなたが二人いると思ったら without のに would sound like
the author actually started to believe there is another あなた ("now that I think
there are two _anata_...").

This 何か歎かむ is a rhetorical question ("what will I grieve about?" → "I won't
grieve about anything"), so its modern literal translation should be 何を嘆こう,
not 何 **か** を嘆こう.

**EDIT:** I think it's possible to use 思ったら in combination with のに to
translate this waka into modern Japanese (あなたが二人いると思ったら何も嘆かない(でいい) **のに** ),
but then the rhetorical question part would have to be less literal.

