It would seem to me the author, like Kant himself, draws the wrong conclusion. Kant’s philosophizing–his obsession with reason and with transcending and separating from his body and its sensations–was likely the RESULT of unprocessed emotions.
When I study Western history, it is in large measure the history of IDEAS, when ideas are only a part of the human experience. There is no history of practice, so much. Yes, various churches had various practices. The Romans practiced sacrifice. They kept altars. Christians began singing early on, and took the Eucharist and wine and practiced baptism.
But these are all outer, social rites. Only in things like the practices of St. Ignatius does one find something possibly useful for personal growth. In the modern era, even most psychology has been useless or even harmful. Only perhaps in the past 30-40 years have useful things like cognitive psychology and positive psychology, and trauma therapies come into being.
To this I would oppose the many spiritual practices of the East, like yoga, and various meditations, and my favorite, Kum Nye.
I wonder if one could summarize modernity as the collective realization that ideas do not provide spiritual food.
And I wonder if we could view the advent of Christianity as the substitution of orthodoxy for orthopraxy. How often does one see the latter word in the history of the West? Virtually never.