Ghosts, animals, agents, and the vocabulary Karpathy gave to AI behavior.

Originally published on Lei Hua's Substack .

Anchors:

2025-10-01 · Animals vs Ghosts (blog post) · https://karpathy.bearblog.dev/animals-vs-ghosts/

2025-10-17 · Dwarkesh Podcast · AGI is still a decade away · https://www.dwarkesh.com/p/andrej-karpathy

2025-11-29 · The space of minds (blog post) · https://karpathy.bearblog.dev/the-space-of-minds/

2025-12-19 · 2025 LLM Year in Review · https://karpathy.bearblog.dev/year-in-review-2025/

Epigraph

"Today's frontier LLM research is not about building animals. It is about summoning ghosts. ... It's possible that ghosts:animals :: planes:birds."

— Andrej Karpathy, Animals vs Ghosts · 2025-10

I. The Eve

October 1, 2025. Sixteen days before he would appear on Dwarkesh's podcast. On this day he posted an essay on his bearblog titled Animals vs Ghosts .

The essay was a response to another Dwarkesh episode — the interview with Richard Sutton (yes, the "Bitter Lesson" Sutton).…