Half Truthful
Logic puzzles require you to think. You will have to be logical in your reasoning.
Three Paley brothers and three Thomson brothers operate a company that manufactures lie detectors. Three of these six men always tell the truth, and three always tell lies; neither set of brothers consists exclusively of liars. Some recent statements from the six men are recorded below. Can you find the six men's full names, and tell which men tell the truth and which tell lies?
1. Alan: "Both my brothers tell lies."
2. Boris: "Both my brothers tell the truth."
3: Chuck: "Alan and Boris are both liars."
4. Dalman: "Chuck and I are brothers."
5. Edwin: "Boris and I are brothers."
6. Finney: "Edwin tells the truth."
7. Finney: "Boris is one of the Paleys."
Answer
Alan Thompson, Liar
Boris Paley, liar
Chuck Thomson, truthteller
Dalman Paley, liar
Edwin Paley, truthteller
Finney Thomson, truthteller
Neither set of brothers consists entirely of liars (introduction), so neither consists entirely of truthtellers, either. Boris, then, can't be telling the truth (clue 2); Boris is a liar. If Alan lies, then Chuck tells the truth (clue 3), and vice versa, so between Alan and Chuck, one is a liar and one a truthteller. By elimination, Dalman, Edwin, and Finney are, in some order, one liar and two truthtellers. If Finney is a liar, so is Edwin (clue 6), which is impossible; so Finney tells the truth and so does Edwin (Clue 6); Dalman, then, is a liar. Boris is a Paley (clue 7). Edwin is a Paley (clue 5). Chuck and Dalman are not brothers (clue 4), so one is a Paley and the other a Thomson; by elimination, Alan and Finney are both Thomsons. Finney Thomson tells the truth, so Alan Thomson is a liar (clue 1) and Chuck is a truthteller (clue 3). Boris Paley lied when he said both of his brothers tell the truth (clue 2); one of his brothers is Edwin Paley, a truthteller, so the other must be a liar  and therefore the third Paley can't be Chuck, a truthteller, so must be Dalman, a liar. By elimination, Chuck is a Thompson.
...got it?
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Comments
OsgoodeLaw
Jul 12, 2002
 Fantastic puzzel! 
im_para_noid
Jul 13, 2002
 eegads man, that is truly confusing 
Piffle
Jul 14, 2002
 Truly a mindboggler. good job 
Dina_2002
Jul 17, 2002
 got it after about an hour of taking notes and stuff. my brain hurts :( wonderful teaser 
jasin
Jul 17, 2002
 extremely confusing but well thought ot good job.

tommo
Aug 06, 2002
 I enjoyed it. 
kkats4
Aug 06, 2002
 eegads!!!!!! LOL! 
sillywilly
Aug 06, 2002
 I think this one is already on this site under a different name (about 60% sure). It's a good puzzle in any case. 
zangel3000
Aug 20, 2002
 I thought that I had rated this one b4like sillywilly's thinking, maybe there's a double. 
dumbell
Aug 20, 2002
 boy am I glad I don't get charged by the minute for internet connection. this would have cost me a small fortune. Well done. 
c13urly
Aug 22, 2002
 How do you jump to Boris being a "LIAR" with no facts? 
ADAMANT545
Oct 08, 2002
 WUT DO U MEAN U CANT PUT MY TEASER ON BOBBRT OR WUTEVER U R 
taniapereira99
Jul 29, 2003
 Broris can only be a liar because if he was truthful, his two brothers would be truthful  making the three other brothers liars  which can't happen as stated in the question. VERY GOOD Teaser! one of my favs cuz it took me a while to solve!! 
energizer74
Jun 25, 2004
 This teaser seems a lot like part of the movie "Labyrinth." She encounters two doors, each with two characters, two lie and the other two tell the truth, and she has to figure out which door leads to the castle and which one leads to certain death. Good teaser nonetheless, a logical brainbuster. 
shelleyz
Jun 25, 2004
 wow really confusing, lots of thinking , it takes quite a while to get it.. great one 
jmcleod
Jun 25, 2004
 That was one of the best on the site. If it was original, great job. 
vbfreak55
Jun 27, 2004
 wow! that was WAY too confusing for me!! i gave up! i don't like this one, sorry! 
gabe1991
Jun 29, 2004
 
marigold
Feb 12, 2005
 No I don't get it! I usually enjoy your teasers, but this one bombed!!! 
shenqiang
Nov 15, 2005
 "neither set of brothers consists exclusively of liars" is redundant. It can be deduced from Alan's statement. 
precious1026
Jan 07, 2009
 Hoe can something that at first glance make no sense, then on second thought have possibilities of a solution be fun? This Teaser is difficult, boring and possess no true answer other then
six brothers have the capacity to lie, and six brothers have the ability to tell the Truth. 
emu77alu02
Jan 07, 2009
 This was challenging, but so fun! I love logic teaserswhen I finally solve them, I feel like I really accomplished something. And my brain feels stretched! 
builder
Jan 07, 2009
 these take time but everything fits if you read the clues carefully, Good job 
doehead
Jan 07, 2009
 If you can unscramble your brain, it becomes fairly easy. 
Marijah
Jan 07, 2009
 i dont know what everyone is getting pissy about this was cute and actually pretty easy
well done sweetie 
kauphi1976
Jan 07, 2009
 everything fit together perfectly.. took like 10 mins though.. was a fun way to start a wed morning :) 
UptheHill
Jan 07, 2009
 Didn't get it!!! 
bradon182001
Jan 07, 2009
 I guess it was well thought out, but I got lost right at the start. Thanks anyways, for posting. 
Oinky08
Jan 07, 2009
 gawd. hard from the start til the end.. 
braniannd
Jan 08, 2009
 i don't get it at all it hurts my brain 
rainbirdbrain
Mar 01, 2009
 Took me about 15 minutes but I got it! Good one! 
jaycr
Jan 07, 2012
 It would seem that there are some liars out there.... hmmm 
gghali
Jan 07, 2012
 That was awesome! It took a long time, but definitely well worth the effort. Great work. 
cutebug
Jan 07, 2012
 It made my brain work hard this morning,but it prevailed.Great mental workout. Hi to a couple of YOUNG ladies on I met on briangle. 
auntiesis
Jan 07, 2012
 For me the second line gave the first big clue, after that it became easy as long as you didn't become too confused. Loved it. 
mepapa
Jan 07, 2012
 I don't care for these logic style. and by the way I think there is a little more deer fly too cute bug then cute bug let's on. 
DarylK
Jan 07, 2012
 True, the first to points are the best hints.
Took me 3 hours to solve this, haha 
DarylK
Jan 07, 2012
 first two* 
skippington
Jan 07, 2012
 this is a basic logic grid puzzle. if you like this kind of puzzle just google "how to solve a logic grid puzzle." if you draw out the grid, it only takes a minute or two to solve. 
dsjt
Jan 09, 2012
 Excellent puzzle. And I'm not lying! 
DarylK
Dec 19, 2012
 best liartruth puzzle of all time. 
paytonmb
Jan 08, 2015
 This "answer" to this puzzle depends solely on the fact you know Alan and Chuck are brothers at the beginning which you don't figure out till after you know who tells the truth and who is lying. The whole explanation is incorrect to figure out the answer. Below is the following order of events and how you should solve this puzzle, the other way is confusing.
***If you look at all the clues after you determine Boris is a liar none are much help until you get to Finney. If you play with the idea Finney tells the truth then Edwin tells the truth too but no other information is reveled except that Edwin and Boris are brothers with the last name Paley. You know there are two more liars and one more truth teller with no way to identify them.
If you start at the top again and say Alan is a truth teller that would make both Chuck and Dalman liars and brothers which is impossible (Clue 4). So now you know Alan is a liar which makes Chuck a truth teller (Clue 3) and thus makes Dalman the final liar.
Now you come to the issue of last names. Chuck and Dalman are not brothers (Clue 4) and so by elimination Alan and Finney are both Thomsons. Boris Paley lied when he said both of his brothers tell the truth so because Edwin, who is already determined to be his brother tells the truth, Dalman must be the other brother because he is a liar. By elimination, Chuck is a Thompson.*** 
Ajabu
Jan 28, 2017
 I got a different answer. And it seems to work.
Alan Paley  Truth
Edwin Paley  Liar
Finny Paley  Liar
Boris Thompson  Liar
Chuck Thompson  Liar
Dalman Thompson  Truth
Boris we know must be a liar. But Edwin could be a liar. In that case Finny too is a liar. Working the clues from there seems to give a different but correct answer from the one given in the teaser. 
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