“No form of Nature is inferior to Art; for the arts merely imitate natural forms.”

Source: Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter LXV: On the first cause, Line 3.

As quoted in Modern Dancing and Dancers (1912) by John Ernest Crawford Flitch, p. 105.
Context: To seek in nature the fairest forms and to find the movement which expresses the soul of these forms — this is the art of the dancer. It is from nature alone that the dancer must draw his inspirations, in the same manner as the sculptor, with whom he has so many affinities. Rodin has said: "To produce good sculpture it is not necessary to copy the works of antiquity; it is necessary first of all to regard the works of nature, and to see in those of the classics only the method by which they have interpreted nature." Rodin is right; and in my art I have by no means copied, as has been supposed, the figures of Greek vases, friezes and paintings. From them I have learned to regard nature, and when certain of my movements recall the gestures that are seen in works of art, it is only because, like them, they are drawn from the grand natural source.
My inspiration has been drawn from trees, from waves, from clouds, from the sympathies that exist between passion and the storm, between gentleness and the soft breeze, and the like, and I always endeavour to put into my movements a little of that divine continuity which gives to the whole of nature its beauty and its life.

Northern Memoirs, written in 1658 and published in 1694 along with another work by Franck, The Contemplative and Practical Angler

As quoted by a former student "TJ" (23 March 2006) http://yesandblog.blogspot.com/2006_03_01_yesandblog_archive.html

The Origins of Art (1966)
Other Quotes
Context: What I am searching for... is some formula that would combine individual initiative with universal values, and that combination would give us a truly organic form. Form, which we discover in nature by analysis, is obstinately mathematical in its manifestations—which is to say that creation in art requires thought and deliberation. But this is not to say that form can be reduced to a formula. In every work of art it must be re-created, but that too is true of every work of nature. Art differs from nature not in its organic form, but in its human origins: in the fact that it is not God or a machine that makes a work of art, but an individual with his instincts and intuitions, with his sensibility and his mind, searching relentlessly for the perfection that is neither in mind nor in nature, but in the unknown. I do not mean this in an other-worldly sense, only that the form of the flower is unknown to the seed.

As quoted in Hans Hofmann (2000) by James Yohe
1970s and later

Source: The Limits of Evolution, and Other Essays, Illustrating the Metaphysical Theory of Personal Ideaalism (1905), The Art-Principle as Represented in Poetry, p.201-2

R. G. Collingwood (1925). "Plato’s philosophy of art." In: Mind. Vaduz, vol. XXXIV, pp.156-7