The spiritual correlative of what we find externally in the world as the relations between the signs of the Zodiac and the seven planets familiar in Spiritual Science.
Rudolf Steiner, Human and Cosmic Thought: Lecture III
When we sleep our astral body separates from the etheric body, only connected with the silver cord. When we wake again the two bodies connects again and in that short time before they are joined fully, the dreams are transferred from the astral body to volatile memory in the etherbody.
When the two bodies are rightly joined we have no spiritual access to the astral world, but for some people the two bodies don’t join fully, there is a rift between them which can be used by natural clairvoyants or there can be created a rift through drugs or other means.
Love – Initiation – The Dark Night of the Soul
Emmanuel Swedenborg, the Swedish scientist and mystic, held that the soul of a man was a 'spiritual fluid' diffused throughout the body, and that the medium for its diffusion was the blood, which was thus imbued with power from the divine source. On the other hand the French occultist Eliphas Levi spoke of blood as 'the astral light made manifest in matter', the astral light in this context being the vital principle of the etheric world.
Blood was regarded by all peoples throughout history as a magic substance of tremendous psychic potency and was therefore universally hedged in by taboos. It was the sign of supreme sacrifice; it sealed covenants; it betokened both maidenly virtue and the magic power of virgins. If split on the earth blood cried aloud for vengeance...'There is scarcely any natural object with so profoundly emotional an effect as blood'.
Benjamin Walker, Beyond the Body: The Human Double and the Astral Planes