In terms of literature pertaining to the subject, I think it is useful to look beyond climbing specific resources. I have found a lot “eastern thought” to be very useful and there are a few books and things that I refer to on a regular basis:
-Tao te ching
-Zen flesh Zen Bones
-Thich Nhat Hanh (Author)
-Alan Watts (popularized eastern thought to a western audience, there is a ton of youtube dialogs)
-Don Juan series by Carlos Castenada
-Jack Kerouac also has a lot pertaining to the Dharma and eastern thought
I think reading this type of literature, you naturally make connections of how it relates to climbing for your self. As oppose to something like Rock Warriors Way where those connections are essentially made for you. I believe it is in the intro of RWW, Arno references the Don Juan series, which tipped me off to those books but don’t have anything to do with climbing! In the movie Chasing Mavericks, a classic story of mentor and mentee pertaining to big wave surfing, the mentor talks about the “four pillars” physical, mental, emotional, and spiritual. It seems sometimes in climbing, we forgot about the spiritual pillar while focusing mainly on the mental and physical. The spiritual pillar is fundamentally different from the mental pillar or “mental strength” although they have strong connections.
In terms of climbing specific lit. I enjoyed:
-Freedom Climbers by Bernadette McDonald (profiles Polish Himalayan Climbing)
-The High Lonesome by John Long (compilation of several stories about soloing)
-The Alchemy of Action by Doug Robinson (Talks about runners high for climbers and flow states)
Hope this helps! Anyone have other literature suggestions?