From Fritz Kreisler’s chapter, “Personality in Art,” in Frederick H. Martens’s Violin Mastery (1919), a book of interviews with violinists from Ysaÿe to Heifetz:
What makes one man an artist and keeps another an amateur is a God-given instinct for the artistically and musically right. It is not a thing to be explained, but to be felt. There is often only a narrow line of demarcation between the artistically right and wrong. Yet nearly every real artist will be found to agree as to when and when not that boundary has been overstepped. Sincerity and personality as well as disinterestedness, an expression of himself in his art that is absolutely honest, these, I believe, are ideals which every artist should cherish and try to realize. I believe, furthermore, that these ideals will come more and more into their own; that after the war there will be a great uplift, and that Art will realize to the full its value as a humanizing factor in life.
Two things make it better in context.
“After the war” was not abstract for him. Kreisler served in the Austrian army and was wounded on the Russian front in 1914. In 1917, once America entered the war, anti-German feeling pushed him off American stages. Predicting a great uplift for Art from there takes faith.
Then “absolutely honest.” For decades Kreisler played pieces he said he’d found in old manuscripts, by Pugnani, Couperin and others. In 1935 he admitted he had written them himself.