Dear Howard,
Glad to remind you of your teacher, Professor Scharfe. As his book is in German, it has not drawn as much attention in the Anglophone world.
Itaretarāśraya is like a chicken and egg argument. Apratiṣṭhāna, as brought up in the Brahmasūtra [tarkāpratiṣṭhānād anyathānumeyam iti ced evam api avimokṣaprasaṅgaḥ] says that all Tarka is apratiṣṭhita, and hence even if we bring up a superior Tarka, that superior Tarka can be shown to be faulty by an even more superior Tarka. Thus, there is a resulting Avimokṣa "no final solution." In an interesting way, this argument reminds me of a line from Śāntideva's Bodhicaryāvatāra "bādhyante dhīviśeṣeṇa yogino 'py uttarottaraiḥ" [this attribution is from my aging memory]. Here the argument is that any Yogic experience can be superseded by a higher level Yogic experience. This is also a sort of Anavasthā.
Many systems have placed arbitrary limits to avoid Anavasthā. For example, according to the Nyāya-Vaiśrṣikas, there is a relationship of Saṃyoga between the monkey and the branch upon which the monkey is sitting. Now the Saṃyoga as a Guṇa relates to the monkey with the relation of Samavāya, and the same Saṃyoga relates to the branch with another Samavāya. Fine, but then what relation would connect the Samavāya to Saṃyoga? Does this need another Samavāya? So there is an interesting regresso ad infinitum situation. But the Nyāya-Vaiśeṣikas say that no further relation is needed to connect a Samavāya to Saṃyoga. But this is quite arbitrary.
Thanks for bringing up this topic. Best wishes,
Madhav
Madhav M. Deshpande
Professor Emeritus, Sanskrit and Linguistics
University of Michigan, Ann Arbor, Michigan, USAg
Senior Fellow, Oxford Center for Hindu Studies
Adjunct Professor, National Institute of Advanced Studies, Bangalore, India
[Residence: Campbell, California, USA]