WASHINGTON, Oct 3 — Dario Amodei says he is not part of it. But the Anthropic chief’s personal and professional circle is entwined with Effective Altruism (EA), a philanthropic movement that has become one of the most contested ideas in Washington and Silicon Valley.

To its proponents, EA is a rational, evidence-based way to do good. To many in the Trump administration, it fuels unfounded and exaggerated fears about artificial intelligence — the kind of warnings Amodei has become known for.

Here are some facts about EA:

Philosophical roots 

EA is a loosely defined movement that uses evidence and reason to work out how to do the most good with a person’s money and time.