Dharmakīrti’s third logical reason holds that non-cognition （anupalabdhi） can establish the absence of an object under the condition that the object in question is perceptible （dṛśya）. In the analysis by Dharmottara, the perceptibility （dṛśyatva） of the object is identified as the presence of both the object itself and all the other causal factors, e.g., light. However, how can we determine the perceptibility of an object when the object itself is absent? According to Watanabe 2001, Dharmottara holds that it is by means of superimposition （samāropa） that one can comprehend the perceptibility of an object whether it is naturally perceptible or imperceptible, such as a pot or a piśāca-demon, respectively. In other words, Watanabe assumes that there is only one pattern of setting the perceptibility of objects in Dharmottara’s system, i.e., superimposition; however, this is not the case. This paper shows that Dharmottara exhibits at least three patterns when dealing with different objects: 1） Objects that are generally perceptible, e.g., pots; 2） Objects that are generally imperceptible, e.g., piśāca-demons; 3） Objects that are generally perceptible but become imperceptible in a specific situation, e.g., fire in a room being imperceptible from the outside.
