Regarding setss - all of the discussions about 'sets containing themselves' or not would not appear to work that well - without concrete examples.
It's a matter of definition. What is a set is determined by the axioms. And the versions of set theory that are used (because they are consistent) have NO sets that contain themselves.I guess I could get on chatgpt and Copilot and ask them to give concrete examples of sets that contain themselves versus those that don't - but Elroch and Martin seem quite well informed though.
Russell and other greats don't seem to give examples in their more famous pronouncements. Why not?
You can easily define such an example in Naive Set Theory (the formal system implicitly used before it was found to be inconsistent). Since in this system it is legitimate to define a set (of sets) by a property, you can define the set of all sets (the property being used is the one that is true for every set). This set can be deduced to be a member of itself.
Unfortunately, it is just as easy in this system to define the set of all sets that do not contain themselves as an element (that is a valid property), and we know that this leads to a paradox, proving Naive Set Theory inconsistent.
Well - back in those days who was their principle audience?
In other words the principle audience of the great mathematicians of the past?
The answer would appear to be: each other.
The more you go back - the more you see that the pioneers of maths and philosophy and science mainly talked to each other.
They still do: they are the people who can understand the details!Various causes of that. For one - very few could read or write.
For two - the pioneers were mostly nobles or bigshots or landowners. Whatever.
For three education was primitive or non-existent.
The fourth one - no internet - is more double-edged.
The internet is an instrument of information and education but unfortunately its also an instrument of disinformation and misguidance and 'reverse education' and negative indoctrination.
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'Sets that contain themselves'
That ice cube shouldn't be that hard to break.
Lets see first though - if an AI sledgehammer is needed to break it.
Shouldn't be.
If Daneel Olivaw was here maybe he might say 'Come on - use internet search to get the examples. Don't use AI.'
Correct. Or you could read the above and see that:
- What is a set depends on the formal system you choose to use
- The consistent set theories that are used don't have any sets that contain themselves as an element
- Inconsistent set theories can include sets that contain themselves, but such systems are worthless. EVERY statement and its negation is "true" in such systems, so truth is meaningless.
drifting in the ocean all alone