INVARIABLENESS • FREE TRANSLATOR.ORG • Definition of Invariableness

... transcendental operation in causal movement as this can be satisfactorily explained by molecular movement (parispanda). There is nothing except the invariable time relation (antecedence and sequence) between the cause and the effect, but the mere invariableness of an antecedent does not suffice to make it the cause of what succeeds; it must be an unconditional antecedent as well (anyathasiddhis'unyasya niyatapurvavarttita). Unconditionality and invariability are indispensable for karyakara@na-bhava or cause and effect relation. For example, the non-essential ...

— A History of Indian Philosophy, Vol. 1 • Surendranath Dasgupta