Upright, the High Priestess is a mysterious card, both frightening and wonderful. Where the Magician is the charismatic showman with an audience, the HPS is the solitary lady guarding an ancient library. Where the Magician is all about possibilities, she is about "impossibilities." Secret knowledge, instincts, even magic. Hers is a card about personal and individual journeys across dark deserts to enlightenment.
She is also about that moment when opposites both exist but don't cancel each other out. When we stand between the pillars of light and dark, day and night...and need that secret knowledge or instincts or psychic power in order to know how to best develop what we have (Example: the Two of Wands - it isn't a choice between a wand and a pentacle, it's two wands. Rather like Harry Potter, the querent needs a wand to do the job, but which wand will best do the job? And how do you start using it?--another example might be a tarot reader deciding on that first deck...and first book to read!).
1) Opposite: Once again, there are negatives in the card that a reader might save for reversals. In this case, secrets are kept or not revealed, the answer is searched for but not found, instincts are wrong. In a more personal sense, there is a cold streak to the High Priestess. She refuses to open the door, withholds her secrets except when they're hurtful. She's that nasty maiden aunt who lives alone and knows the dirt on everyone and uses it just to watch them squirm.
She can also be that unpredictable teacher or woman - brilliant but her mood changes are downright scary. You don't know if she's going to coldly answer your question - or bite your head off.
2) Blocked: The blocking here really focuses on the instinctual or psychic energy. There is just nothing coming through. Once of those days when you do a tarot reading and the cards are just cards. They don't speak to you, you see nothing in them. Likewise, making a decision about anything seems impossible. The two wands look the same and you cannot tell the difference between them.
3) Upside-down: There would seem to be little difference if we turn the card upside-down, but like the subtle meaning of the High Priestess, the difference is similarly subtle. Taking the Rider-Waite image, she has the crescent moon at her foot and a well-spring of water begins there that runs through other cards.
Turn her upside-down and the water falls and runs dry. The moon hangs above rather than at her command. The curtain of pomegranates, shrouding the mysteries falls open, and all that people should not see - that might be damaging to see - they see. The pillars are on their crowns not on the base and cannot support themselves.
There is, in short, a loss of control. And the High Priestess, who holds opposites in delicate balance, needs that control. If all this is lost, then there is a kind of madness. Chaos, indecision, a loss of secrets and knowledge.
Curious about this card when upright? Go to our Tarot Card Meanings.