Rules and Exceptions
1. For every rule there is an exception (premise).
Ergo,
2. The rule for every rule there is an exception itself must have an exception (subconclusion).
Ergo,
3. There are some rules that have no exceptions (main conclusion).
Topics to discuss:
1. The problem of induction (Hume)
2. Self-reference
3. Others (the choice is yours)
Ergo,
2. The rule for every rule there is an exception itself must have an exception (subconclusion).
Ergo,
3. There are some rules that have no exceptions (main conclusion).
Topics to discuss:
1. The problem of induction (Hume)
2. Self-reference
3. Others (the choice is yours)
Comments (34)
I wish I could think of an intelligent response. Of course, there are logical similarities with Russell's Paradox and the Cretan Liar. But right now I can't think of a knock-down philosophical analysis (memo to self: ease up on the Semillon when browsing philosophy forums!)
4. 1. is false. (RAA)
It is indeed as simple as that.
Why in my view is correct.
This is why mathematics isn't just one enormous tautology.
Quoting alan1000
Sorry, I don't follow.
Quoting Bartricks
1 implies 2. Bartricks, you got this!
Quoting 180 Proof
You mean self-contradictory? Implicit in the notion of rules is the nonexistence of exceptions.
Quoting jgill
Are you sure?
Yes, quite sure. "Rule" is an ill-defined entity that can be an axiom, a law, a tautology or simply a statistical likelihood. It's a well known saying much used by parents and politicians to excuse their hypocrisy.
Ethics? The alleged inadequacies of utilitarianism & Kantianism?
No, parents and politicians.
I see! :up:
Eg. "It's wrong to kill."
"Exception": "It's ok to kill in self-defense"
If its true that killing is ok in some situations, it means that killing isn't wrong. It is just wrong in some circumstances.
A more obvious example:
"Its wrong to pick fruit from trees".
"exception": "Its ok to pick fruit from a tree if it's your tree, or you have permission"
There are rules that are partial and others that are complete and by that I mean partial rules apply in most cases while complete ones all the time. Both would qualify as rules, oui?
It used to be considered a rule that swans are white.
Now its common knowledge that there are a minority of swans that are black.
Does this mean the rule, "Swans are white" is true in most cases? While, say, "Swans are birds." is a complete rule?
If I was before a black swan, and someone says "Swans are white", I could say, "You are mostly right, but completely wrong in this case".
I dunno, its a word game for me at this point.
No. Like I wrote, "equivalent to a tautology" (i.e. self-repetitive, lacks information) because a "rule without exception" is inapplicable (i.e. applied in every case is, in effect, applied in no case).
:up:
Imagine every rule has an exception. Well then the proposition 'every rule has an exception' is true. That doesn't make that a rule. It's not dictating anything.
Imagine I say "Britain has laws". Is that a law? No.
So 2 is false and 1 is true.
How is it a tautology? Either I don't know what tautology is or you've got the wrong end of the stick. The former is more likely. Do explain if you don't mind, please!
1. Every rule has an exception (premise)
1 is a rule, ja?
If it is then, necessary that 1 itself has exceptions i.e. [math]\downarrow[/math]
2. There are some rules that have no exceptions.
Bartricks, I'm depending on you to sort this out. You can do it!
Never say never or always. I'm exploring the intuition expressed therein.
In some legal systems (guessing here so cum grano salis) judgment is based on general features (how similar is the case to others?) and special features (what is unique about the case?).
Ergo,
2. The rule 1 itself has exceptions.
Ergo,
3. There are rules (1 for example) that have exceptions.
4. Statements 1 contradicts statement 3.
Ergo,
5. Statement 1 is false
Ergo,
6. There are rules that have no exceptions.
What are these rules? They seem the kind we can use to build a robust system on/around.
No, I think Bartricks is right. A rule prescribes, it doesn't describe. That every rule has an exception, were it true, is a description, not a prescription, and so 1 isn't a rule.
Although, I suppose, you could make a rule that says that every rule must have an exception, but then it's up to you if this rule applies to itself or just to every other rule, and so it's up to you if you want to introduce a contradiction or not.
Man-made rules, on the other hand, are invented and aren't inviolable. Such rules are prescriptive first and then, subsequently, descriptive.
The rule that every rule has an exception is, like the laws of nature, first descriptive i.e. we study rules and find out that the words "all" "no" (re categorical logic) have very limited applicability, due to special cases in which rules are (apparently) broken.
No problemo! Muchas gracias.
So how could we ever come to the conclusion that every rule has an exception? Because we'd also have to find an exception to the rule that every rule has an exception, i.e. find a rule that doesn't have an exception. But then we'd never come to the conclusion that every rule has an exception in the first place.
The point to my argument is that the rule all rules have exceptions ultimately contradicts itself, leading us to the conclusion there are rules without exceptions. In a sense, I've deduced that some rules simply can't be broken (no matter what).
This imposes restrictions on God's omnipotence; s/he/it can't do anything s/he/it wishes (a corollary, a side note only).
I tried but desired to establish a connection between there are rules without exceptions and Hume's problem of induction i.e. can we prove that the laws of nature are the rules without exceptions?
Perhaps there's just one rule without an exception, that rule being "for every rule except this one there is an exception".
Can you work that out for me, please?
:up: Indeed!
Easy!
(1) Is said to be a premise, not a rule. Then (2) calls it and treats it as a rule! So (2) is invalid or not applicable.
Have you something more difficult? :smile: