Disagreeing with a teacher's instruction
Disagreement with a teacher is not disloyalty in this tradition; the Buddha invited investigation of himself and said that even his own teaching was a raft. The passages here are about how to hold a view honestly — saying what you believe without claiming it is the only truth — and about the timing and manner of saying a hard thing to someone you respect. They do not settle the technical question. Try the instruction long enough to have something to report, then report it; a good teacher wants the data.
What the suttas say
don’t go by oral transmission, don’t go by lineage, don’t go by testament, don’t go by canonical authority, don’t rely on logic, don’t rely on inference, don’t go by reasoned train of thought, don’t go by the acceptance of a view after deliberation, don’t go by the appearance of competence, and don’t think “The ascetic is our respected teacher.” But when you know for yourselves:
The Kālāma discourse — the canon's charter for testing teachings.
Where this stops: It is not permission to believe whatever one likes; it ends with what the wise praise. Never a reason to stay with a teacher who is doing harm.
AN 3.65:25.3–25.4 · With the Kālāmas of Kesamutta
Mā anussavena, mā paramparāya, mā itikirāya, mā piṭakasampadānena, mā takkahetu, mā nayahetu, mā ākāraparivitakkena, mā diṭṭhinijjhānakkhantiyā, mā bhabbarūpatāya, mā samaṇo no garūti. Yadā tumhe kālāmā attanāva jāneyyātha:
Mendicants, a mendicant who is an inquirer, unable to encompass another’s mind, should scrutinize the Realized One for two things—things that can be seen and heard: ‘Can anything corrupt be seen or heard in the Realized One or not?’ Scrutinizing him they find that nothing corrupt can be seen or heard in the Realized One.
The Buddha's own instructions for scrutinizing a teacher, including himself.
Where this stops: Never a reason to stay with a teacher who is doing harm.
MN 47:4.1–4.4 · The Inquirer
Vīmaṁsakena, bhikkhave, bhikkhunā parassa cetopariyāyaṁ ajānantena dvīsu dhammesu tathāgato samannesitabbo cakkhusotaviññeyyesu dhammesu: ‘ye saṅkiliṭṭhā cakkhusotaviññeyyā dhammā, saṁvijjanti vā te tathāgatassa no vā’ti? Tamenaṁ samannesamāno evaṁ jānāti: ‘ye saṅkiliṭṭhā cakkhusotaviññeyyā dhammā, na te tathāgatassa saṁvijjantī’ti.
“In the same way, prince, the Realized One does not utter speech that he knows to be untrue, false, and pointless, and which is disliked by others. The Realized One does not utter speech that he knows to be true and correct, but which is harmful and disliked by others. The Realized One knows the right time to speak so as to explain what he knows to be true, correct, and beneficial, but which is disliked by others. The Realized One does not utter speech that he knows to be untrue, false, and pointless, but which is liked by others. The Realized One does not utter speech that he knows to be true and correct, but which is harmful, even if it is liked by others. The Realized One knows the right time to speak so as to explain what he knows to be true, correct, and beneficial, and which is liked by others. Why is that? Because the Realized One has sympathy for sentient beings.”
Prince Abhaya — the test for whether and when to say a hard thing.
Where this stops: For deciding whether and when to say one particular hard thing; it does not judge a relationship as a whole, and it is not a reason to say nothing. Nor does it mean anyone owes another person news about their own body, health or pregnancy, or should speak when speaking would put them at risk.
MN 58:8.1–8.8 · With Prince Abhaya
“Evameva kho, rājakumāra, yaṁ tathāgato vācaṁ jānāti abhūtaṁ atacchaṁ anatthasaṁhitaṁ sā ca paresaṁ appiyā amanāpā, na taṁ tathāgato vācaṁ bhāsati. Yampi tathāgato vācaṁ jānāti bhūtaṁ tacchaṁ anatthasaṁhitaṁ sā ca paresaṁ appiyā amanāpā, tampi tathāgato vācaṁ na bhāsati. Yañca kho tathāgato vācaṁ jānāti bhūtaṁ tacchaṁ atthasaṁhitaṁ sā ca paresaṁ appiyā amanāpā, tatra kālaññū tathāgato hoti tassā vācāya veyyākaraṇāya. Yaṁ tathāgato vācaṁ jānāti abhūtaṁ atacchaṁ anatthasaṁhitaṁ sā ca paresaṁ piyā manāpā, na taṁ tathāgato vācaṁ bhāsati. Yampi tathāgato vācaṁ jānāti bhūtaṁ tacchaṁ anatthasaṁhitaṁ sā ca paresaṁ piyā manāpā tampi tathāgato vācaṁ na bhāsati. Yañca tathāgato vācaṁ jānāti bhūtaṁ tacchaṁ atthasaṁhitaṁ sā ca paresaṁ piyā manāpā, tatra kālaññū tathāgato hoti tassā vācāya veyyākaraṇāya. Taṁ kissa hetu? Atthi, rājakumāra, tathāgatassa sattesu anukampā”ti.
Mendicants, these four things can be known in four situations. What four? You can get to know a person’s ethics by living with them. But only after a long time, not casually; only when attentive, not when inattentive; and only by the wise, not the witless. You can get to know a person’s purity by dealing with them. … You can get to know a person’s resilience in times of trouble. … You can get to know a person’s wisdom by discussion. But only after a long time, not casually; only when attentive, not when inattentive; and only by the wise, not the witless.
How a person is actually known — over a long time, with attention, from close up — a standard that applies to a teacher as much as to anyone.
Where this stops: It counsels patience before trusting and before condemning; it is not a reason to stay close to someone already known to be doing harm.
AN 4.192:1.1–1.6 · Facts
Cattārimāni, bhikkhave, ṭhānāni catūhi ṭhānehi veditabbāni. Katamāni cattāri? Saṁvāsena, bhikkhave, sīlaṁ veditabbaṁ, tañca kho dīghena addhunā, na ittaraṁ; manasikarotā, no amanasikarotā; paññavatā, no duppaññena. Saṁvohārena, bhikkhave, soceyyaṁ veditabbaṁ, tañca kho dīghena addhunā, na ittaraṁ; manasikarotā, no amanasikarotā; paññavatā, no duppaññena. Āpadāsu, bhikkhave, thāmo veditabbo, so ca kho dīghena addhunā, na ittaraṁ; manasikarotā, no amanasikarotā; paññavatā, no duppaññena. Sākacchāya, bhikkhave, paññā veditabbā, sā ca kho dīghena addhunā, na ittaraṁ; manasikarotā, no amanasikarotā; paññavatā, no duppaññenāti.
For a sensible person who is preserving truth this is not sufficient to come to the categorical conclusion: ‘This is the only truth, anything else is futile.’ “But worthy Gotama, how do you define the preservation of truth?” If a person has faith, they preserve truth by saying, ‘Such is my faith.’
How to hold a view without dishonesty on either side.
MN 95:14.14–15.4 · With Caṅkī
Saccamanurakkhatā, bhāradvāja, viññunā purisena nālamettha ekaṁsena niṭṭhaṁ gantuṁ: ‘idameva saccaṁ, moghamaññan’ti. “Kittāvatā pana, bho gotama, saccānurakkhaṇā hoti, kittāvatā saccamanurakkhati? Saccānurakkhaṇaṁ mayaṁ bhavantaṁ gotamaṁ pucchāmā”ti. Saddhā cepi, bhāradvāja, purisassa hoti; ‘evaṁ me saddhā’ti—