It is a well-known fact that the Śaiva nondualistic philosopher Utpaladeva (fl. c. 925–975) adopted the Sāṃkhya principle according to which the effect must exist in some way before the operation of its cause (satkāryavāda). Johannes Bronkhorst has highlighted the paradox inherent in this appropriation: Utpaladeva is a staunch supporter of the satkāryavāda, but whereas Sāṃkhya authors consider it as a means of proving the existence of an unconscious matter, the Śaiva exploits it so as to establish his monistic idealism, in perfect contradiction with the Sāṃkhya dualism of matter and consciousness. How does Utpaladeva achieve this complete reversal of meaning of the satkāryavāda? The present article argues that the elliptical verses of the Īśvarapratyabhijñākārikā dealing with this issue have been partly misunderstood so far due to the loss of Utpaladeva’s own detailed commentary (Vivr̥ti) on this passage: Abhinavagupta’s two commentaries, however terse in this respect, clearly show that a crucial part of Utpaladeva’s reasoning remains implicit in the verses. The article therefore attempts to reconstruct the gist of Utpaladeva’s strategy by having recourse to various other Śaiva sources, including Somānanda’s Śivadr̥ṣṭi and Utpaladeva’s own commentary thereon. This examination shows that Utpaladeva’s appropriation of the satkāryavāda rests on a profound transformation of the Sāṃkhya notions of manifestation (abhivyakti) and potentiality (śakti), and that his criticism of the Sāṃkhya understanding of causality might target the Śaiva dualists as well as Sāṃkhya authors.