# Citing difference requires similarity? **URL:** \ **Category:** Great Debates\ **Created:** [January 28, 2010, 5:32pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787 "2010-01-28T17:32:09Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 5:32pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/1 "2010-01-28T17:32:09Z")
I have heard this idea mentioned before: In order to find a difference between two things, there must be some area of similarity (i.e. some common substrate, although abstract concepts would require a figurative substrate). To be more specific, this similarity is derived **from** the difference. Anyone have an opinion on this assertion? (or good counterexamples?) Example: a newspaper and a magazine are different because magazines are generally glossy while newspapers are matte. Similarity = both are made of paper. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [January 28, 2010, 5:59pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/2 "2010-01-28T17:59:18Z")
> [@petew83](#): > > Example: a newspaper and a magazine are different because magazines are generally glossy while newspapers are matte. Similarity = both are made of paper. I’ve never seen this. Certainly not on this MB. Do you have a cite? And be sure it is similar. 🙂 ---
**Author:** ![Burton](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Burton](https://boards.straightdope.com/u/Burton)\ **Post date:** [January 28, 2010, 6:13pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/3 "2010-01-28T18:13:26Z")
How would you find the difference between a brick and a marsh mellow since one is made from clay the other sugar? Eat both? Build with both? ---
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 6:25pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/4 "2010-01-28T18:25:26Z")
> [@](#): > > How would you find the difference between a brick and a marsh mellow since one is made from clay the other sugar? Eat both? Build with both? First you have to name the particular difference you want to point out. For your example you could say: A brick is made of clay and a marshmallow is made of sugar, ergo both are solid objects composed of a uniform substrate. ---
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 6:28pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/5 "2010-01-28T18:28:02Z")
> [@](#): > > I’ve never seen this. Certainly not on this MB. Do you have a cite? And be sure it is similar. [http://www.megafoundation.org/CTMU/Articles/Langan\_CTMU\_092902.pdf](http://www.megafoundation.org/CTMU/Articles/Langan_CTMU_092902.pdf) page 16 bottom ---
**Author:** ![Burton](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Burton](https://boards.straightdope.com/u/Burton)\ **Post date:** [January 28, 2010, 6:33pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/6 "2010-01-28T18:33:17Z")
“…ergo both are solid objects composed of a uniform substrate.” Isn’t that so broad as to be kind of meaningless? It seems like the long way around to to me. ---
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 6:46pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/7 "2010-01-28T18:46:12Z")
> [@](#): > > Isn’t that so broad as to be kind of meaningless? It seems like the long way around to to me. I believe it’s just as broad as the difference stated. ---
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 6:53pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/8 "2010-01-28T18:53:16Z")
> [@](#): > > I believe it’s just as broad as the difference stated. Probably better to say the similarity sits one level above the difference stated. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 28, 2010, 8:41pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/9 "2010-01-28T20:41:35Z")
OK, then, what’s the difference between a sense of duty and a Lego brick? ---
**Author:** ![Strassia](https://avatars.discourse-cdn.com/v4/letter/s/e8c25b/32.png) [@Strassia](https://boards.straightdope.com/u/Strassia)\ **Post date:** [January 28, 2010, 9:02pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/10 "2010-01-28T21:02:17Z")
I think it has more to do with frame of reference(although that may not be the best term). If two things share no frame of reference, then why are you comparing them in the first place? What is the point? In your example (newspapers v. magazines), there are a number of significant differences, but they only matter in how you are examining them. As media for storing information (glossy lasts longer and has less residue)? As fuel (glossy has more toxic chemicals released)? Without the frame of reference, what does the difference matter? In other words, you have to ask “why should I care?” This will lead you to the frame of reference. Newspapers are matte and magazines are glossy: Why should I care? Because one leaves ink on your fingers when you read it, but is cheaper to produce. We now know the frame of reference is things you can read. Compare that to the statement: Slate roofing tiles are matte and magazines are glossy. Why should I care? I can’t think of a single reason why that difference would matter to me. There for the comparison is meaningless because the two objects share no meaningful frame of reference. Jonathan ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [January 28, 2010, 9:31pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/11 "2010-01-28T21:31:46Z")
> [@Chronos](#): > > OK, then, what’s the difference between a sense of duty and a Lego brick? One must always adhere to one’s Lego brick. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 28, 2010, 9:33pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/12 "2010-01-28T21:33:01Z")
> [@Chronos](#): > > OK, then, what’s the difference between a sense of duty and a Lego brick? This is where the argument falls down, I think - they’re certainly different, because one is a concept or state of mind and the other is a physical object made of plastic. Their similarity? - they’re both ‘things’ that can be described in words. Or in other words, the argument is pointless. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 28, 2010, 9:34pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/13 "2010-01-28T21:34:45Z")
> [@Strassia](#): > > I think it has more to do with frame of reference(although that may not be the best term). If two things share no frame of reference, then why are you comparing them in the first place? What is the point? In your example (newspapers v. magazines), there are a number of significant differences, but they only matter in how you are examining them. As media for storing information (glossy lasts longer and has less residue)? As fuel (glossy has more toxic chemicals released)? Without the frame of reference, what does the difference matter? > > In other words, you have to ask “why should I care?” This will lead you to the frame of reference. Newspapers are matte and magazines are glossy: Why should I care? Because one leaves ink on your fingers when you read it, but is cheaper to produce. We now know the frame of reference is things you can read. > > Compare that to the statement: Slate roofing tiles are matte and magazines are glossy. Why should I care? I can’t think of a single reason why that difference would matter to me. There for the comparison is meaningless because the two objects share no meaningful frame of reference. > > Jonathan This is a silly and artificial imposition on the process of comparison. How can we even _tell_ that magazines and roofing tiles have (supposedly) no common frame of reference _without first comparing them_? Remind me not to send you shopping. ---
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 9:40pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/14 "2010-01-28T21:40:40Z")
> [@](#): > > OK, then, what’s the difference between a sense of duty and a Lego brick? A specific difference must be stated. The more difficult it is to state a difference, the more distant the two concepts are. > [@](#): > > Slate roofing tiles are matte and magazines are glossy. That’s a more general difference, because you are allowing the glossy/matte dichotomy to exist for any two different mediums. Therefore the similarity will be very general as well: both are flat surfaces. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 28, 2010, 9:45pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/15 "2010-01-28T21:45:02Z")
> [@petew83](#): > > A specific difference must be stated. The more difficult it is to state a difference, the more distant the two concepts are. This seems completely back-to-front to me. A sense of duty is different from a lego brick because the latter is a material object and the former is a state of mind. Now, what is the _similarity_ between those two things that permitted me to discern the difference? ---
**Author:** ![Strassia](https://avatars.discourse-cdn.com/v4/letter/s/e8c25b/32.png) [@Strassia](https://boards.straightdope.com/u/Strassia)\ **Post date:** [January 28, 2010, 10:18pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/16 "2010-01-28T22:18:21Z")
> [@Mangetout](#): > > This is a silly and artificial imposition on the process of comparison. How can we even _tell_ that magazines and roofing tiles have (supposedly) no common frame of reference _without first comparing them_? > > Remind me not to send you shopping. I think the problem is one of us does not understand what the OP’s point is (and I fully acknowledge it could be me). I think he is referring to the fact that if someone states Item A is different (or better/worse) than Item B in manner X, someone else will come in and say that it is not a valid comparison because A and B are totally different and not meant to be compared. My point is about how to tell if a comparison is valid. I think we all agree that finding differences in crispiness between Lays potato chips and the store brand are completely valid. But if I say that Lays potato chips are less crispy than wine glasses, I have left the frame of reference and my statement is essentially meaningless. In a less far fetched example comparing Lays potato chips to broccoli, it helps to determine what the frame of reference is. If it is food in general the comparison is valid. If it is food available in the vending machine downstairs from me, it is not. Jonathan ---
**Author:** ![petew83](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@petew83](https://boards.straightdope.com/u/petew83)\ **Post date:** [January 28, 2010, 10:36pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/17 "2010-01-28T22:36:44Z")
> [@](#): > > A sense of duty is different from a lego brick because the latter is a material object and the former is a state of mind. Now, what is the similarity between those two things that permitted me to discern the difference? That’s about as general a difference as you can get. The similarity must be even more general than the stated difference, and I believe it would require deep knowledge of cognitive science. My best current attempt would be: A ‘lego brick’ is a material object while a ‘sense of duty’ is state of mind, ergo they both share a certain concept level in your mind (a common substrate of conception). ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 29, 2010, 12:29am UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/18 "2010-01-29T00:29:36Z")
> [@petew83](#): > > That’s about as general a difference as you can get. The similarity must be even more general than the stated difference, and I believe it would require deep knowledge of cognitive science. > > My best current attempt would be: A ‘lego brick’ is a material object while a ‘sense of duty’ is state of mind, ergo they both share a certain concept level in your mind (a common substrate of conception). Except that this isn’t what we do when we decide that Lego is different from duty. We don’t derive the difference from some general similarity - the difference is evident in the form of absent similarity. ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [January 29, 2010, 10:23am UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/19 "2010-01-29T10:23:53Z")
> [@petew83](#): > > A specific difference must be stated. The more difficult it is to state a difference, the more distant the two concepts are. I don’t know. I can sum up the differences between Legos and a sense of duty with “they have nothing meaningful in common.” Describing the difference between Legos and [Mega Bloks](http://en.wikipedia.org/wiki/Mega_Bloks) would likely take more than 6 words, but Mega Bloks have more in common with Legos than a sense of duty does. ---
**Author:** ![kevlaw](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kevlaw/32/2281_2.png) [@kevlaw](https://boards.straightdope.com/u/kevlaw)\ **Post date:** [January 29, 2010, 4:18pm UTC](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787/20 "2010-01-29T16:18:28Z")
> [@petew83](#): > > My best current attempt would be: A ‘lego brick’ is a material object while a ‘sense of duty’ is state of mind, ergo they both share a certain concept level in your mind (a common substrate of conception). I can up with the similar: They both exist as concepts, only the lego block exists as a material object. [Next page](https://boards.straightdope.com/t/citing-difference-requires-similarity/526787.md?page=2)