Distinguishing Etheric and Astral

In my reading of Rudolf Steiner I came across a fourfold division of Beings into what he called "bodies" but which might better be understood as "levels". 

Ego - Astral - Etheric - Physical*

The first and last are easy to grasp - Ego is me-my real-self which is eternal; and Physical is the mortal material body. 

But although there seems to me to be some validity to Steiner's posited in-between levels of Etheric and Astral, I have found it difficult to understand, distinguish and grasp these - especially when I see how the terms sometimes get used in practice.

For instance Steiner sometimes tries to draw a bright-line between the levels, and use them to divide and separate discrete categories of minerals, plants, animals and humans - on the basis that the etheric plane corresponds to "life"; the astral to "consciousness", and the ego to something-like "will". 

For Steiner (in some of his writings) plants are minerals plus the etheric; animals are plants plus the astral; humans are animals plus the ego. 

However; I believe that all Beings have all these attributes, but to widely varying degrees...

Such that we are talking about distinctions, not divisions; levels not planes or "bodies". 

So; to make coherent sense from these "planes" I think it must be acknowledged that all Beings (mineral, plant and animal) have all these planes of reality to some degree, but in widely varying degrees.

It could reasonably be decided to merge etheric and astral, to regard them as a continuum bridging the spiritual qualities in-between our mortal physical bodies and the eternal true-self. 

And this must be true in an ultimate sense. Nonetheless, the fact that these levels are often distinguished suggests that individual consideration may have value. 

Here are some thoughts on distinguishing Etheric and Astral that seem broadly valid:

The Etheric "field"

This realm is localized, and surrounds the physical body - extending into the surroundings but falling off rapidly with distance.  

The etheric can be understood as rather like a "field" surrounding the body - it is both sensory and imposes itself. For example, the etheric field is what enables people to realize that another person, or large animal, is near; or if we are being watched. 

We can reach-out with our etheric field to explore our surroundings, so it operates as a sixth sense - in addition what is perceptible to "the five senses". 

Charisma and sexual "chemistry" operate mostly at the etheric level - and so do "gut feelings" of fear, and the perception of threat from others. 

In such situations, our own etheric field interacts-with another person's etheric field; in a way that is qualitatively distinguishable from the five senses. 

It is by etheric communications that we may feel comfortable and happy to sit in silence beside those we love; and feel uncomfortable and miserable when we are nearby those whom we regard as hostile or manipulating. 

By etheric interaction we may be aware, and we may influence - and etheric interactions may be spontaneous and passive; or they may be active and willed.

Someone may project their dominance or their sex appeal etherically - entering the room and all attention is upon them. Or people may project the opposite. 

Or even withdraw their etheric field; to the point of a kind of willed etheric-invisibility, so they tend to pass un-noticed. 

The etheric level is also that of ghosts and the like: localized spirits, spirits tied to a place or situation; spirits that may be detected by our etheric awareness, and many interact directly with physical bodies. 

The Astral "realm"

The astral is de-localized, it is more like a realm than a field - a realm that we may enter and explore; and in which distance is irrelevant, and past and present are both experienced.

The astral is the realm of dreams. 

In dreaming we (mostly) leave-behind our everyday physical bodies and our etheric awareness - the dreamer lying on the bed asleep; and our egos instead travel in astral realms, equipped with astral "simulations" of the body and etheric field. 

In the astral realm of dreaming we may interact with other Beings using five physical sense plus the etheric - but in the astral realm these are "virtual" communications, all-but detached from the sleeping person's physical self, who is mostly cut-off from his surroundings. 

Since Beings are eternal and not localized - the astral realm potentially extends across all reality. 

In the astral realm we can therefore interact with those who have died, and those from far away - from anywhere and from past or present; in an as-if fashion, communicating by quasi-sensory virtual-versions of vision, language, touch etc.  

[In the Astral we are not "in" the past, not re-living it; but instead may experience here-and-now the past of our own earlier experience (including our pre-mortal experience as spirits), and also here-and-now experience the past as has been experienced by the other Beings we encounter.] 

But the astral is a realm that includes all Beings - to some degree. 

Therefore we should not suppose that the astral is wholly, or even mostly, "good". It is not a realm exclusively for wish-fulfilment and pleasure. 

Since we inhabit primary creation, and since the astral is a realm in this mortal world, the astral is potentially open to all manner of Beings; although the ego remains conscious and always retains a measure of control - and of responsibility. 

The evil we encounter and do in the astral realm, is some kind of reality, for which we bear some kind of responsibility - which is why dreams are important. 

But the astral realm is not only a matter of dreaming; it is always present to some degree; and may be substantially or (almost) fully entered in other circumstances: for instance in meditation or trance states, in intoxication and delirium states.  

When we are aware of a kind of inner pressure to think, travel, read or otherwise do something; this may be a matter of communications from other Beings operating at the astral level. 

Astrally-communicating Beings may be good and loving (perhaps benign ancestors, or our beloved who have died, or those who love from their books or music or suchlike). However, just as in this mortal world; among these well-meaning benign Beings, none are infallible, and some are much wiser than others. 

But the astral Beings trying to influence us may instead be hostile. The thoughts and activities that these Beings encourage will be intended to harm us, spiritually.  

In other words (amongst others) the astral realm is that in which we are most likely to encounter both angels and demons; and our guide must be a combination of our own discernment with the guidance of the Holy Ghost - which guidance is above and independent from the astral realm. 

The astral realm is a realm of indirect communication; in which our interactions are symbolic and perceptual (even the etheric is a kind of perception) and require interpretation. 

While the level "above" the astral is that of the Ego, the real, ultimate, divine Beings that populate creation. 

And at this level where there is direct and unmediated - Being to Being - knowing. 

*My understanding is that this division - or at least this formulation of it - originated in Theosophy, and with Helena Blavatsky. Steiner began as a Theosophist. The idea therefore spread far beyond Steiner, and both in the West and the East (Gandhi was a Theosophist in his early adulthood, thus Theosophy influenced modern Hinduism. Several Theosophical concepts - such as Atlantis - have been widely incorporated into the New Age. So the etheric and astral are discussed all over the place.