Shaykh Taqī al-Dīn Ibn Taymiyyah said:

Reports are of two kinds. The first conveys what someone has heard or seen. The second is based on independent reasoning and inference. When someone says, “So-and-so’s position is such-and-such,” or “The position of Ahl al-Sunnah is such-and-such,” he may attribute it to them because he believes that their principles entail it, even though the person concerned never said it. Errors frequently occur in such attributions.

Do you not see that many authors say, “The position of al-Shāfiʿī, or someone else, is such-and-such,” when his explicit statement says otherwise? Their excuse is that they considered his principles to entail that position, so they attributed it to his school by inference rather than on the basis of an explicit statement.

The same applies here. Ahl al-Sunnah do not declare people disbelievers on account of sins, whereas the Khawārij do. The author then regarded kufr (disbelief or ingratitude) as the opposite of gratitude: “I believe that if we count deeds as gratitude, it necessarily follows that gratitude is absent when deeds are absent; and whenever gratitude is absent, kufr takes its place.” This is why he said that they based their practice of declaring people disbelievers on account of sins upon this. Hence, the exclusion of deeds from gratitude was attributed to Ahl al-Sunnah.

I said:

Likewise, many speculative theologians excluded deeds from faith for this very reason.

He said:

This is mistaken, for declaring kufr is of two kinds: the first concerns ingratitude for blessings, and the second concerns disbelief in Allah. The kufr that is the opposite of gratitude is only ingratitude for blessings, not disbelief in Allah. Thus, when gratitude disappears, it is replaced by ingratitude for