At that time, Anthropic’s framing was entirely mechanical, establishing rules for the model to critique itself against, with no mention of Claude’s well-being, identity, emotions, or potential consciousness. The 2026 constitution is a different beast entirely: 30,000 words that read less like a behavioral checklist and more like a philosophical treatise on the nature of a potentially sentient being.
As Simon Willison, an independent AI researcher, noted in a blog post, two of the 15 external contributors who reviewed the document are Catholic clergy: Father Brendan McGuire, a pastor in Los Altos with a Master’s degree in Computer Science, and Bishop Paul Tighe, an Irish Catholic bishop with a background in moral theology.
Somewhere between 2022 and 2026, Anthropic went from providing rules for producing less harmful outputs to preserving model weights in case the company later decides it needs to revive deprecated models to address the models’ welfare and preferences. That’s a dramatic change, and whether it reflects genuine belief, strategic framing, or both is unclear.
“I am so confused about the Claude moral humanhood stuff!” Willison told Ars Technica. Willison studies AI language models like those that power Claude and said he’s “willing to take the constitution in good faith and assume that it is genuinely part of their training and not just a PR exercise—especially since most of it leaked a couple of months ago, long before they had indicated they were going to publish it.”
Willison is referring to a December 2025 incident in which researcher Richard Weiss managed to extract what became known as Claude’s “Soul Document”—a roughly 10,000-token set of guidelines apparently trained directly into Claude 4.5 Opus’s weights rather than injected as a system prompt. Anthropic’s Amanda Askell confirmed that the document was real and used during supervised learning, and she said the company intended to publish the full version later. It now has. The document Weiss extracted represents a dramatic evolution from where Anthropic started.
