 While Pāṇini uses the term prakṛti to refer to the derivationally original state of a word or expression before changes effected by grammatical operations are applied, Kātyāyana and Patañjali use the term vikṛta to refer to the derivationally transformed segment. However, change and identity are not compatible within more rigid metaphysical frameworks, and this becomes apparent in the following discussion. In his Vārttikas or comments on Pāṇini’s grammar, Kātyāyana says that one could have argued that an item partially transformed does not yet lose its identity (Vārttika 10 on P. 1.1.56). But such an acceptance would lead to non-eternality (anityatva) of language (Vārttika 11, Mahābhāṣya, I, p. 136), and that is not acceptable. Patañjali asserts that words in reality are eternal (nitya), and that means they must be absolutely free from change or transformation and fixed in their nature. If words are truly eternal, one cannot then say that a word was transformed and is yet the same. This points to the emerging ideological shifts in philosophical traditions, which make their headway into the tradition of grammar, and finally lead to the development of newer conceptions within the tradition of grammar and elsewhere.