Anonymous  +  612301 Tue, 16 Dec 08 07:14 PM (As originally found here). Last night a school was vandalised by youths on motorbikes who were pulling wheelies on the football pitch. Stuart Brown owns a motorcycle. The question: Stuart may have been one of the youths who vandalised the school. Answer can be (A. True) (B. False) or (C. Impossible to tell.) Anonymous Football, Sports

	Clive  +  612372 Tue, 16 Dec 08 08:43 PM Hi, As originally found here). Last night a school was vandalised by youths on motorbikes who were pulling wheelies on the football pitch. Stuart Brown owns a motorcycle. The question: Stuart may have been one of the youths who vandalised the school. Answer can be (A. True) (B. False) or (C. Impossible to tell.) Before I try to answer, let me first ask you to consider how you would answer in the above categories for these statements. Stuart may be 75 years old. Stuart may have been in jail last night. Stuart may not know how to pull a wheelie. Stuart may have been in a submarine under the Atlantic ocean last night. Do you see any difference between my questions and yours? Best wishes, Clive Clive Joined on Thu, Oct 28 2004 Canada Veteran Member 29,668 El tango argentino es un pensamiento triste que se puede bailar (The tango argentino is a sad thought which can be danced) Enrique Santos Discépolo Difference Between, Football, Sports

	Clive  +  612404 Tue, 16 Dec 08 09:25 PM Hi, If 'true' means 'It is true that Stuart may have been . . . ', then I'd say the original statement and my statements are all true.  If 'true' means that 'Stuart was one of the youths who did this', then the answer is that it is impossible to tell, based on the facts as given. In the context of a 'may' statement, I interpret C to mean the rather awkward 'It is impossible to tell if it is possible that  . . . '.   It's pretty hard to understand this. In such problem statements, anything is possible, unless we are given facts that show it is not possible.  Best wishes, Clive   Clive Context

	CalifJim  +  618745 Tue, 23 Dec 08 05:38 AM Years ago, my logic teacher said, "Any statement of the form 'It may be the case that ...' is always true." In fact, he even wrote the "truth table" on the board: X   :                       |   true   |     false It may be that X  :   |   true   |     true Thus:  'It may be that the moon is made of cheese' is true, i.e., 'The moon may be made of cheese' is true. According to 'formal logic' then, the answer is A. Whether the rules of 'formal logic' are the same as those of 'ordinary language logic' is an open question.  It appears to me that 'matters of fact' are more important in 'ordinary language logic', so that in ordinary language 'The moon may be made of cheese' is false because we know for various reasons that the moon is not, as a matter of fact, made of cheese. CJ CalifJim Joined on Mon, Aug 2 2004 California Veteran Member 22,463 "There are no facts, only interpretations" - Nietzsche Languages

	MrPedantic  +  619586 Tue, 23 Dec 08 11:31 PM I would say that the "may" statement is true for any of these 2nd statements: 1. Stuart has been on the school football pitch. 2. Stuart has vandalised a school. 3. Stuart has a motorbike. 4. Stuart is a youth. 5. Stuart exists. 6. Stuart likes coffee. 7. Stuart is reading this thread in horror. or even: 8. MrP MrPedantic Joined on Tue, Oct 12 2004 Veteran Member 12,592 ...opella forensis / adducit febris... Football, Sports

	Kooyeen  +  620375 Wed, 24 Dec 08 04:17 PM CalifJim “Years ago, my logic teacher said, "Any statement of the form 'It may be the case that ...' is always true."” That is interesting, and I was going to agree, but then I realized there are some faults after seeing your example "The moon may be made of cheese"... It's not made of cheese, so everyone would answer "that's false". MAY means "possible with probability greater than 0". The moon may be made of cheese ---> It is possible with probability greater than 0 that the moon is made of cheese: - True if the fact "the moon is made of cheese" has been associated with a probability P greater than 0 - False if it has been associated with a probability P = 0 So it can only be true if you don't believe in science, you are suspicious anyway, or you don't know anything about the moon. So the original question can be seen this way: Last night a school was vandalised by youths on motorbikes who were pulling wheelies on the football pitch. Stuart Brown owns a motorcycle. Stuart may have been one of the youths who vandalised the school. ---> It is possible he's one of those who vandalized the school - True if we associate the fact Stuart was among them with a probability P > 0 - False if that's impossible and we associate it with P = 0 - Impossible to tell if we don't associate that event with a probability From the information we have, we can't exclude Stuart from the list of suspects, and so we can't associate the fact with P = 0. If you think it's impossible to tell, not associating a probability would mean you are not willing to express an opinion, so it's not a sensible answer. So I guess that statement is true. If we knew Stuart was an old man, it would have to be excluded, the associated probability would be 0, and the statement would be false. Kooyeen Joined on Thu, Dec 22 2005 Italy Senior Member 4,981 Parental Advisory / Explicit Posts Football, Sports, Mistakes

	CalifJim  +  620430 Wed, 24 Dec 08 05:28 PM Kooyeen “MAY means "possible with probability greater than 0".” That's one interpretation. Or.  MAY means "possible in some possible world". But then what does "possible in some possible world" mean? CJ CalifJim