The theory of the microcosm and the macrocosm is a central one to many occult and magical belief-systems, for example the Golden Dawn cosmology, where it is given a practical theurgic application.  This same theory also appears in Rudolph Steiner's teachings.  In an important early (1911) lecture, The Etherisation of the Blood, he refers to this a number of times.

The "three stages of activity of the human soul - the purely intellectual, the aesthetic, and the moral -" are "microcosmic images of the three realms which in the macrocosm.... lie one above the other.  The Astral world is reflected in the world of thought; the Devachanic world in the aesthetic sphere of pleasure and displeasure; and the Higher Devachanic world is reflected as morality [good or bad deeds]." [The Etherisation of the Blood, p.16 (Rudolph Steiner Press, London]

So Thoughts are the Shadow-images of Beings of the Astral plane, Sympathy and Antipathy the Shadow-images of Beings of Lower Devachan, and Moral Impulses the Shadow-images of Beings of Higher Devachan.  [Ibid].

Thus

"We have within us shadow-images of the great Universe and all the members of our constitution - the physical, etheric, astral bodies and the ego - are worlds for Divine Beings." [Ibid, p.38].

Rudolph Steiner