He Wrote That Nobody Would Understand Him

Dharmakirti wrote, in his own book, that nobody would understand it and that his work would be forgotten.

He was wrong about the second part. He may have been right about the first.

Dharmakirti worked around 600 to 670 CE, born in the south, and studied at Nalanda under Dharmapala. By about 650 he was in Magadha and was the most formidable logician alive.

And he is genuinely difficult, not obscure, not badly written, but dense in the way that a proof is dense, where every clause is load-bearing and nothing can be skipped. He knew it. The remark about being forgotten is a real note of bitterness from a man who could see how few people were following him.

Thirteen hundred years later he is required reading in every Tibetan monastic college in the world.

What he inherited

Dignaga had built the frame: two means of knowledge only, perception free of concepts, and apoha, meaning by exclusion.

Dharmakirti's great work is the Pramanavarttika, a commentary on Dignaga, and like Vasubandhu commenting on his own verses, the commentary swallowed the original. It is what people read. He also wrote the Pramanaviniscaya, the Nyayabindu, and the Santanantarasiddhi, that last being an argument about how you could know other minds exist at all.