Holden runs [Open Philanthropy](https://www.openphilanthropy.org/), a philanthropic foundation.
I particularly admire him for the intellectual culture he promotes at Open Philanthropy, and within the effective altruism community more broadly.
His [2021 interview with Ezra Klein](https://www.nytimes.com/2021/10/05/podcasts/transcript-ezra-klein-interviews-holden-karnofsky.html) is the best introduction.
Some blog posts that give a flavour:
* [Worldview diversification](https://www.openphilanthropy.org/blog/worldview-diversification)
* [Sequence Thinking vs Cluster Thinking](https://blog.givewell.org/2014/06/10/sequence-thinking-vs-cluster-thinking/).
* [Update on Cause Prioritization at Open Philanthropy](https://www.openphilanthropy.org/blog/update-cause-prioritization-open-philanthropy)
Through his leadership of Open Philanthropy, his past work at GiveWell and his board seat at OpenAI, he seems on course to make an exceptional contribution.
For more, see his [80,000 Hours interview](https://80000hours.org/podcast/episodes/holden-karnofsky-open-philanthropy/), and his more recent [Ask Me Anything](https://www.youtube.com/watch?v=YMbpPoz9hWQ).
Update July 2021: Holden has a [new blog](https://www.cold-takes.com/).