From Introduction:
Mind priests are the psionically-endowed worshippers of the gods of mentalism, psionic powers and of the mind. They embrace both the divine mysteries of their deity’s embrace and the full glory of their own psionic powers of the mind, often seeing no difference between the two, as the powers of the mind and will are there only because of the will of the deity in question. Mind priests tend to be very driven clerics, those who are driven to exemplify the divine power of the mind as well as the divine magical gifts of their deity.
In the pantheons of the mind, there is the essential duality of power broken between the powers of divine magic, granted by petitioning the gods themselves for power, and the power of psionics, powers granted and unlocked by the gods in all those who can manifest such aptitudes. Yet both are the gift of the godminds, and thus the driven mind priests have worked to enmesh the two studies together.
Only characters who have training both in the arts of the mind and the worship of the divine can become mind priests. Cleric / Psion is the most common class combination, but requires both a high Intelligence and Wisdom. Thus, a fair number of mind priests are Clerics / Psychic Warriors (although they suffer from the low hit die) and there are also some Druid mind priests. As many Clerics have a high Charisma as religious and community leaders, Cleric / Wilder multiclasses are also well represented within the ranks of the mind priests. While the class also works for Paladin / Psychic Warriors, there are very few who follow these paths within the ranks.
Many of the most potent mind priests go on to take levels of thrallherd to secure their position of power in the church and the temporal world. Those less cynical often become loremasters or seek out other, more clerical paths.