I must stay alone and know that I am alone to contemplate and feel nature in full; I have to surrender myself to what encircles me, I have to merge with my clouds and rocks in order to be what I am.
The pure, frank sentiments we hold in our hearts are the only truthful sources of art. A painting which does not take its inspiration from the heart is nothing more than futile juggling. All authentic art is conceived at a sacred moment and nourished in a blessed hour; an inner impulse creates it, often without the artist being aware of it.
Variant translation: The heart is the only true source of art, the language of a pure, child-like soul. Any creation not sprung from this origin can only be artifice. Every true work of art is conceived in a hallowed hour and born in a happy one, from an impulse in the artist's heart, often without his knowledge.
The artist's feeling is his law. Pure sensibility can never be Unnatural; it is always in harmony with nature. But the feelings of another must never be imposed on us as our law. Spiritual relationship produces artistic resemblance, but this relationship is very different from imitation. Whatever one may say about X.'s paintings, and however much they may resemble Y.'s, they originated in him and are his own.