I think that if you want to present Tarnas's ideas as a part of current academic discourse, you might want to find out how his scholarship, produced at the California Institute of Integral Studies' program in Consciousness and Transformation, fits into the larger map of academic discourse today. Who quotes him? Where are his books published? Hint: not in academic presses.

It is fine to discuss Tarnas's ideas for what they are. But there's also context.