Rooth, I have been intriqued w where I first picked up that passage u refered too. After pulling a few books randomly,and being taught w every opened page,something so particular but off topic, and knowing ive read these texts numerous times it strikes me, how we think we know, what is important , yet is so not the case, till we surrender to the creativity that is happening before us.
I think that the idea about oral gratification probably came from texts from the southern Buddhists. Their texts are often filled with teachings on mentality. The text Vissudimagga is an incredable encyclopedia cataloging the process of changing mind states and thought forms. Easier and more available is Jack Kornfields Living Buddhist Masters, its the teachings of about a dozen teachers who implify this tradition which deals with different topics deeply but also reasonable, discursivly.