The one thing that drew her out of her boredom and irritation was the alethiometer. She read it every day, sometimes with Farder Coram and sometimes on her own, and she found that she could sink more and more readily into the calm state in which the symbol meanings clarified themselves, and those great mountain ranges touched by sunlight emerged into vision. ...
"It's almost like talking to someone, only you can't quite hear them, and you feel kind of stupid because they're cleverer than you, only they don't get cross or any thing... And they know such a lot, Farder Coram! As if they knew everything, almost! Mrs. Coulter was clever, she knew ever such a lot, but this is a different kind of knowing... It's like understanding, I suppose..."
He would ask specific questions, and she would search for answers.
"What's Mrs. Coulter doing now?" he'd say, and her hands would move at once, and he'd say, "Tell me what you're doing."
"Well, the Madonna is Mrs. Coulter, and I think my mother when I put the hand there; and the ant is busy-that's easy, that's the top meaning; and the hourglass has got time in its meanings, and partway down there's now, and I just fix my mind on it."
"And how do you know where these meanings are?"
"I kind of see 'em. Or feel 'em rather, like climbing down a ladder at night, you put your foot down and there's another rung. Well, I put my mind down and there's another meaning, and I kind of sense what it is. Then I put 'em all together. There's a trick in it like focusing your eyes."
-- from the golden compass, book one of his dark materials by phillip pullman
that was describing how the main character, lyra, was able to use a fictional truth-telling device called an alethiometer. reading tarot cards works the same way; you can ask a question, and the symbols on the cards will tell your answers.
i have a very unique deck of tarot cards. they are not a traditional deck, but have beautiful watercolor paintings of different symbols such as a star, mermaid, atlas (the man holding the globe on his back), a thief, a drunk, a pine tree, a ladder, a palm tree, different kinds of fruit, etc. they also have numbers on the front, and the name of whatever is on the card ("sun", "star", "maiden", "watermelon", etc). this deck came to me, it found me, and thats how i truly know it not only belongs to me, but is mine. because of this, i can get very good personal readings from them.
much like in the book i quoted above, each card or symbol has many levels of meaning. Dust is what moves the hands of the alethiometer in the book, but what Dust really is is just pure spirit, and that is indeed what moves the tarot cards.