This paper is a preliminary analysis of two among the five definitions of falsity ( mithyātva ) presented by Madhusūdana Sarasvatī (MS) in his magnum opus , the Advaitasiddhi . It is mainly focused on the second and fourth definitions, which at first sight appear to be mere repetitions of one another. The first definition of falsity examined is Prakāśātman’s: “falsity is the property of being the counter-positive of the absolute absence of an entity in the [same] locus in which (...) it is perceived.” The other definition investigated was first given by Citsukha: “falsity is the property of being the counter-positive of the absolute absence residing in its own locus.” The mutual differences among these two definitions will be underlined following MS himself, as well as some other authors of the later Advaita Vedānta textual tradition. (shrink)