Abstract: It is an important issue in the contemporary theory of understanding whether the speaker can transmit understanding to the listener by testimony, which is called the transitivity problem of understanding, is an important issue in the contemporary theory of understanding. Opponents such as Zagzebski argue that understanding is an ability, and that the transmission of understanding involves additional cognitive work, therefore understanding can not be transmitted by testimony. Supporters such as Grimm argue that understanding can be transmitted by testimony, because abilities can be transmitted by testimony, and that understanding does not involve additional cognitive work when the listener has the relevant background abilities and background knowledge. The existing studies in both dimensions adopt qualitative research methods, and mistakenly regard the transitivity problem of understanding as a qualitative question of “yes or no” rather than a quantitative question related to the degrees of cognitive state of subjects. Epistemic gradualism takes a quantitative position and approach, which holds that there are degrees of understanding, and quantify the degree of understanding through the concept of maximum understanding. From the perspective of the degree of understanding, all kinds of understanding can be transmitted by testimony, but the improvement of the listener’s degrees of understanding is different.

Key Words: Understanding; Degrees of understanding; Testimony; Ability; The transitivity problem