What about "dangerous" rather than "evil"? (I also dislike religious and moral terminology for mathematics. I specially dislike the terminology "morally true", which I often hear, although I like the concept.) We frequently encounter dangerous situations in our mathematical paths, no matter how hard we try to avoid them, but if we know what we are doing it is ok. In this discussion about "evilness", what is important is to know that lack of invariance under isomorphisms is dangerous (and why this is so), and that you must consciously know how to properly proceed if your definition happens to be not invariant, be it for necessity, lack of a better idea, or mere convenience. MHE Joyal wrote:
Dear Juergen,
You wrote:
Let me start by proposing "equi-unstable" and "precarious" as possible replacements for "evil".
I agree that we should explore various options. Strickly speaking, there is no need for a new terminology since "non-invariant" has been used in the past and it is working pretty well.
Let me draw a list of potential names. I have added a few:
non-invariant equi-unstable precarious unstable fragile private
I invite everyone to contribute to the list.
Best, AJ
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