Age of Bronze, Middelheim, Antwerp
Doubt can serve you well, if you train it. It must become a way of knowing, a good critic. Every time doubt wants to spoil something for you, ask why it finds something ugly and demand proofs. Thus tested by you, doubt may become bewildered and embarrassed, even aggressive. But don't give in, demand reasons and be persistent and attentive every single time, and the day will come when, instead of a destroyer, he will become one of your best servants—perhaps one of the most intelligent of those who help you build your life.
Furnborg, Jonsered, Sweden, November 4, 1904
Letters to a Young Poet