Near the end of the Īśvarapratyabhijñākārikā, his verses on recognising the Lord, Utpaladeva gives an image for what the whole book is for. A woman has begged and prayed for her lover to come, and now he stands beside her; but as long as she does not know him, he looks like any other man and gives her no joy. The self, he argues, is in the same position. It is already the Lord of all things, and that changes nothing until it is recognised. This book established a school of Kashmiri Śaiva philosophy, devoted to Shiva, and the school took its name from recognition, pratyabhijñā. Its central claim is plain: nothing has to be gained, only seen.
His life is almost blank. In the book's last verse he names himself only as Utpala, son of Udayākara, who set out this recognition so that people could succeed without effort. Historians place him in Kashmir in the first half of the tenth century. His teacher was Somānanda, whose Śivadṛṣṭi, "the vision of Shiva", was the school's first treatise, and Utpaladeva wrote a commentary on it. In the closing section of his own book he calls the path new, straight and easy: Somānanda first pointed it out, and Utpaladeva made it convincing by argument, so that whoever practises it is freed while still alive.
The argument was aimed at the Buddhist logicians who followed Dharmakīrti, the seventh-century theorist of knowledge. They denied any lasting self: a person, for them, is a stream of momentary cognitions, each gone as soon as it has occurred. Utpaladeva accepts the moments and asks what joins a memory to the experience it remembers, when that experience has already vanished. His answer is a single knower that persists through both. That knower is not a mirror that merely shows things. Its essence is vimarśa, reflective self-awareness, and Utpaladeva identifies this with the Lord's own knowing and acting. In a short treatise, the Ajaḍapramātṛsiddhi, he turns the Buddhists' own test of reality against them: a thing counts as real if it produces an effect, but an effect counts only for someone who registers it. He builds the case from experience and inference rather than from the authority of scripture, and Abhinavagupta, his most famous successor, read his main book as a single proof set out for others.
The logician was also a devotee. The first verse of the Īśvarapratyabhijñākārikā says he has somehow become a servant of the Great Lord; the rest of the book argues that every person already is that Lord. He also wrote devotional hymns to Shiva, the Śivastotrāvalī, which his disciples arranged after him into twenty hymns, and Kṣemarāja, a pupil of Abhinavagupta, wrote a commentary on them.
The teaching passed through his pupil Lakṣmaṇagupta to Abhinavagupta, who wrote two commentaries on the Īśvarapratyabhijñākārikā, one of them on a longer prose gloss by Utpaladeva of which only fragments now survive. Raffaele Torella, the Italian scholar who edited the book in 1994, judged that most of Abhinavagupta's ideas develop what Utpaladeva had already said. Torella's edition also printed Utpaladeva's own short gloss complete for the first time, from a single manuscript he found in the library at Trivandrum, in the far south of India.