Is there any elegant and succinct way to translate “穷则变，变则通，通则久” to English? I felt the translation could be quite lengthy when I tried to explain every single character. Thank you very much.
Impasse is followed by change, and change will lead to a solution.
(provr.) Quand on est à bout, on change, dès que l’on a changé, on aboutit : dès qu’un changement s’est amorçé, une solution peut voir le jour. De tout s’avise à qui pain faut; nécessité est mère d’industrie, d’invention.
The last part is quite sums it up in quite a nice succienct way: necessity is the mother of invention.
“穷则变，变则通，通则久” is just the poetic way of saying "变通".
"变通" means be flexible and improvise. Direct translation of each character means; "变" to change, "通" to get through (the problem).
Poetic translation: When you are poor (穷) in resources, you will need to innovate with changes (变). Once you got through (通) the problem, your changes will last (久).