Gratitude (Stanford Encyclopedia of Philosophy)

As a response to beneficence, gratitude seems to include certain judgments or beliefs—at the very least, the belief that an act of beneficence has occurred (Berger 1975: 302; Walker 1980–1981: 51; Manela 2019).

In the absence of such judgments, we would be hard pressed to call a beneficiary grateful.

A beneficiary who failed to judge that an act of beneficence had been performed would be unlikely to have the feelings or exhibit the behaviors a grateful person ought to have and do (see sections 3.2, 3.3, and 3.4 below).

https://plato.stanford.edu/entries/gratitude/#EleGraRes