“I go to nature to be soothed and healed, and to have my senses put in order.”

Source: Aleph

To which of the warring serpents should I turn with the problem that now faces me?
It is easy, and tempting, to choose the god of Science. Now I would not for a moment have you suppose that I am one of those idiots who scorns Science, merely because it is always twisting and turning, and sometimes shedding its skin, like the serpent that is its symbol. It is a powerful god indeed but it is what the students of ancient gods called a shape-shifter, and sometimes a trickster.
Can a Doctor Be a Humanist? (1984).

De Kooning's lecture Trans/formation, at Studio 35, 1950.
1950's

J 65
Aphorisms (1765-1799), Notebook J (1789)
Context: A great speech is easy to learn by heart and a great poem even easier. How hard it would be to memorize as many words linked together senselessly, or a speech in a foreign tongue! Sense and understanding thus come to the aid of memory. Sense is order and order is in the last resort conformity with our nature. When we speak rationally we are only speaking in accordance with the nature of our being. That is why we devise genera and species in the case of plants and animals. The hypotheses we make belong here too: we are obliged to have them because otherwise we would unable to retain things... The question is, however, whether everything is legible to us. Certainly experiment and reflection enable us to introduce a significance into what is not legible, either to us or at all: thus we see faces or landscapes in the sand, though they are certainly not there. The introducion of symmetries belongs here too, silhouettes in inkblots, etc. Likewise the gradation we establish in the order of creatures: all this is not in the things but in us. In general we cannot remember too often that when we observe nature, and especially the ordering of nature, it is always ourselves alone we are observing.

"On Being Idle".
Idle Thoughts of an Idle Fellow (1886)

Source: Night

Quote of Friedrich, 1821; as cited in Authenticity and Fiction in the Russian Literary Journey, 1790-1840 (2000) by Andreas Schönle, p. 108, from memoirs of Vasily Zhukovsky
Variant translation: I have to stay alone in order to fully contemplate and feel nature.
This answer of Friedrich is recorded by Vasily Zhukovsky who asked the painter in 1821 to travel together to Switzerland
1794 - 1840