Books like The Essence of Alan Watts
Alan Watts
The Essence of Alan Watts is 141 pages, about 2 hours 35 minutes at 250 words a minute.
10 books to read next
How long each takes
The Consolation of Philosophy 3.7 h 
I and Thou 2.5 h 
Leisure, the Basis of Culture 2.5 h 
Sex, Ecology, Spirituality 15.6 h 
The Case for God 7.7 h 
Physico-theology 8.1 h 
God's Secret Formula 4.0 h 
God's Debris 2.4 h 
Making Sense of It All 3.9 h 
Wilhelm Schmidt and the Origin of the Idea of God 6.2 h Bar height shows length. Estimated at 250 words a minute.