Science, Wisdom, Knowledge, Education.
The High Priestess is the card of knowledge, instinctual, supernatural, secret knowledge. She holds scrolls of arcane information that she might, or might not reveal to you. The moon crown on her head as well as the crescent by her foot indicates her willingness to illuminate what you otherwise might not see, reveal the secrets you need to know. The High Priestess is also associated with the moon however and can also indicate change or fluxuation, particularily when it comes to your moods.
Hubby says he goes along with this.