To be correct, he maybe didn't coin the term. At least I didn't find it on quick search in his book Cybernetics. Seems like the term ultrastable actually comes

To be correct, he maybe didn't coin the term. At least I didn't find it on quick search in his book Cybernetics. Seems like the term ultrastable actually comes from Ashby [1]. [1] https://users.sussex.ac.uk/~ezequiel/AS/lectures/AdaptiveSystems3.pdf https://users.sussex.ac.uk/~ezequiel/AS/lectures/AdaptiveSys...