Now the proof that one is in contact with an independent entity depends on a sensation which ought to be unmistakeable if one is in good health. One ought not to be liable to mistake ones own sensible impressions for somebody elses! It is only Mans incurable vanity that makes the Astral Strayed Reveller or the mystic confuse his own drunken babble with the voice of the Most High.
The essence of the right sensation consists in recognition of the reality of the other Being. There will be as a rule some element of hostility, even when the reaction is sympathetic. Ones soulmate (even) is not thought of as oneself, at first contact.
One must therefore insist that any real appearance on the Astral Plane gives the sensation of meeting a stranger. One must accept it as independent, be it Archangel or Elf, and measure ones won reaction to it. One must learn from it, though one despise it; and love it, however one loathe it.
One must realize, on writing up the record, that the meeting has effected a definite change in oneself. One must have known and felt something alien, and not merely tried on a new dress.
There must always be some slight pang of pain in a true Astral Vision; it hurts the Self to have to admit the existence of a not-Self; and it taxes the brain to register a new thought. This is true at the first touch, even when exaltation and stimulation result from the joy of making an agreeable contact.
There is a deeper effect of right reaction to a strange Self: the impact invariably tends to break up some complex in the Seer. The class of idea concerned has always been tied up, labelled, and put away. It is now necessary to unpack it, and rearrange its contents. At least, the annoyance is like that of a man who has locked and strapped his bag for a journey, and then finds that he has forgotten his pyjamas. At most, it may revolutionise his ideas of the business, like an old bachelor with settled plans of life who meets a girl once too often.
Any really first-class Astral Vision, even on low planes, should therefore both instruct the Seer, and prepare him for Initiation.
Those failing to pass this test are to be classed as practice.
I, for one, agree with this completely, especially regarding the part about feeling some sort of pain. Every time I invoke a spirit, I feel a slight pain in my solar plexus. Crowley's explanation is that the Self doesn't accept the existence of another, but I always attributed it to the fact that the spirit has a higher, sacred energy, and mine feels belittled and animalistic compared to the spirit's, which is why I feel the "pain".
Or maybe it's because of the straining of energy (the effort) that is necessary to properly reach out and meet the spirit halfway.
As for my own take on confirming a real spiritual presence, I always look for results. There's nothing better that could confirm a real spiritual encounter than getting what you asked for. Sometimes, asking questions about something in the world, which answers can be later verified, is also good. The problem with this is that it is not an immediate verification, but I would consider it more reliable than Crowley's, because we all know the power of the mind and how it can induce all sorts of sensations, if the trance is deep enough (e.g. dreams).
What about you? How do you verify or confirm a real spiritual encounter?