When making nature your teacher you must look deep into the natural world, on the one hand looking at the outside, and on the other getting nourishment from the inside. What is often called getting to the source of your inner self can only be possible through such a coordination of the inner and outer.
「師造化必須深究自然，一方面由外體察，一方面從內孕育，所謂中得心源，須內外配合才可」，是他說過足以代表他寫生精神的一段話。