In Buddhism, acinteyya (Pali), "imponderable" or "incomprehensible," avyākṛta (Sanskrit: अव्याकृत, Pali: avyākata, "unfathomable, unexpounded,"[1]), and atakkāvacara,[2] "beyond the sphere of reason,"[2] are unanswerable questions or undeclared questions.
They are sets of questions that should not be thought about, and which the Buddha refused to answer, since this distracts from practice, and hinders the attainment of liberation.
"[web 1] In Indian philosophy, acinteyya is [T]hat which is to be unavoidably accepted for explaining facts, but which cannot stand the scrutiny of logic.
[3]It is also defined as That which cannot or should not be thought, the unthinkable, incomprehensible, impenetrable, that which transcends the limits of thinking and over which therefore one should not ponder.
[4] Synonymous terms are avyākṛta[4] "indeterminate questions,"[5] and atakkāvacara,[2] "beyond the sphere of reason.
[7] The four imponderables are identified in the Acintita Sutta, Anguttara Nikaya 4.77, as follows:[8] The Cula-Malunkyovada Sutta, MN 63[9] and 72[10] contains a list of ten unanswered questions about certain views (ditthi): In the Aggi-Vacchagotta Sutta,[6] "Discourse to Vatsagotra on the [Simile of] Fire," Majjhima Nikaya 72,[web 3] the Buddha is questioned by Vatsagotra on the "ten indeterminate question:"[5] avyākrta[4] The Buddha refuses to answer the questions, avoiding getting entangled in debate, but answers with a simile:[5] "And suppose someone were to ask you, 'This fire that has gone out in front of you, in which direction from here has it gone?
"Even so, Vaccha, any physical form by which one describing the Tathagata would describe him: That the Tathagata has abandoned, its root destroyed, made like a palmyra stump, deprived of the conditions of development, not destined for future arising.
Freed from the classification of form, Vaccha, the Tathagata is deep, boundless, hard to fathom, like the sea.
The Sabbasava Sutta (Majjhima Nikaya 2[15]) also mentions 16 questions which are seen as "unwise reflection" and lead to attachment to views relating to a self.
Sacca-samyutta, "The Four Noble Truths", Samyutta Nikaya 56:[web 4] Therefore, o monks, do not brood over [any of these views] Such brooding, O monks, is senseless, has nothing to do with genuine pure conduct (s. ādibrahmacariyaka-sīla), does not lead to aversion, detachment, extinction, nor to peace, to full comprehension, enlightenment and Nibbāna, etc.
It is accompanied by suffering, distress, despair, & fever, and it does not lead to disenchantment, dispassion, cessation; to calm, direct knowledge, full Awakening, Unbinding.
[web 3]The Buddha further warns that Whoever speculates about these things would go mad & experience vexation.