A maxim among dozens, written as his mind was approaching the collapse of January 1889. It is not a medical claim and not an instruction to seek damage. He is compressing an older idea, that a capacity can be built by what it survives, into a line the twentieth century turned into a gym proverb. He also wrote, nearby, that if you have your own why of life you can bear almost any how. Frankl quoted that one from a camp.