It would not occur to anyone who takes a compass, a magnetic needle in hand, to seek in the needle itself the cause of its pointing with one end to the North and with the other to the South; the physicist feels himself compelled to regard the magnetic force proceeding from the needle, and the directing magnetic force coming from the North Pole of the earth, as a whole. The cause of what takes place in the small space of the needle is sought in the great universe.
Yet this is not done in other cases where it should be done, and where it is of importance. If anyone — especially a scientist — observes that one living being is formed within another living being, as, for instance, the egg is formed in the body of the hen, he sees there how something forms in the smallest space; but what does not usually strike him is to apply what he knows of the magnetic needle and say, that the reason why the germ of the egg develops in the body of the hen lies in the entire cosmos, not in the hen. Exactly as the great universe has a part in the magnetic needle, so too the whole cosmos has a share in the hen’s body, — no matter what other processes also take part in it — the whole cosmos in its spherical form co-operate. […]
That of course is heresy in the eyes of official science, but it is a truth. The forces of the cosmos co-operate in the most varied ways. Just as it is true that in the case of man (empirical embryology proves this) the head, in its germinal rudiments is formed from the whole universe, — the human head forms first in the maternal organism — so too is it true that, on the other hand, the original causative forces for this formation work from the whole cosmos, and man’s head is an image of it.
Source: Rudolf Steiner – GA 181 – Earthly Death and Cosmic Life: Lecture 2: A Contribution to our Knowledge of the Human Being – Berlin, 29th January, 1918
Translated by Harry Collison