Difference Between a Metaphor and a Simile (A Teacher's Aid): 

Metaphor and simile are quite different, but are commonly confused simply because they are so very similar in nature. This chapter is aimed at clearing up at least some of the confusion, if not the entire sum of the confusion! As you read on, you'll learn why these two are so similar, and how to clearly separate the two. First, have a look at the following two examples.

A good book is like a good meal. A simile suggesting that a book may be as ( mentally) nourishing and satisfying as a meal. A wire is a road for electrons.     A metaphor suggesting that electrons actually do use a wire as a road to travel on.

If I had said above that  "a book is food for thought" rather than "a good book is like a good meal", I would not simply be comparing food and literature, but actually stating that from some perspective they are identical. If I am an avid reader, who hungers for information to digest, gleaning every detail to feed my insatiable appetite for brain candy, literature is not only similar  to food for me - it is food. 

A simile - or to be like something - is to retain some irresolvable difference which means one can never fully substitute for the other. On the other hand, a metaphor actually is a substitution - it is an equation in principle. 

It could be said, then, that:

A metaphor is an equation where a simile is an approximation.

In math, I could say that 99 is approximately equal to (or "like") 100 - that would be a simile - a comparable but different value ("about 100"); but an equation, such as A=B,  means that if A+3=10 then B+3=10. A simile may be difficult to extend further in this way, but the nature of a good metaphor is that it may always be extended, reversed, re-substituted with other elements and so on (just as an algebraic expression* can). In fact, using the above equation, I may also find that another metaphor "C" is also equal to A and B, such that A=B=C. For example:

• A road is a road for cars.
• A wire is a road for electrons. 
• A vein is a road for blood cells.
• The sea is a road for ships.
• The railway is a road for trains.

To show how interchangeable these are, let's look at a few common phrases (metaphors in bold):

• shipping lane/ highway lane (and bowling alley & lane!)
• electric line/ railway line/ shipping line/ gas line
• major artery for traffic
• electric conductor/ train conductor/ bus conductor
• rail road/ iron road
• path of electrons
• traffic flow/ electron flow/ blood flow

(One may even convey a point in their line of conversation by steering the conversation to flow in the direction of a specific avenue)

Sometimes, we will build both a metaphor and a simile from the same parts, showing how incredibly close these two literary devices are. Perhaps this is due to the fact that  the word "like" means both "similar" and "the same". Compare "a car is like a cell: it travels along a vessel of asphalt" with "a car is a cell...". When building a simile, it helps to keep it clearly removed from a metaphor: "clouds like cotton candy" is clearly a simile.

Typically, if it needs further explanation, it's probably a simile; if it makes instant sense, it's most likely a metaphor. The simile is always poetic, while the metaphor always has the ring of truth (perhaps this is why metaphors readily become accepted into language as "dead metaphors", while there is no such thing as a "dead simile").

Basic Rule: If it uses the words "is like" or "is as", it is usually a simile; if it uses the word "is", without "as" or "like", it is usually a metaphor. Caveat: Because there is so much confusion surrounding the difference between metaphor and simile, the two are often misstated. If the word "like" is used to imply similarity, then it is a simile; however, if the word "like" is being used to imply it is "the same", then this is a false simile and is, in fact a metaphor.

Simile:     ABC is approximately equal to DEF;  

Example: "clouds like cotton candy"

"Cloud" = ABC...= WhiteLightGaseous;  

"CottonCandy" = DEF...=WhiteLightSoft

Gaseous is not equal to soft. However, they are similar in their accommodating nature. Though clouds may look like cotton candy, their functions within their respective domains are entirely different. Truthfully, the clouds are not like cotton candy, but they leave a passing impression that they are. A simile is almost always based on our first impressions, which is why the comparison drawn in a simile is always limited.

Metaphor:   ABC equals DEF; A=D, B=E, C=F ; 

Example: "a car is a cell"

"Car" = ABC...= ShellDoorsWheels; 

"Cell" = WallPoresCilia***

 

A car is equal to a cell. Both protect and transport their passengers, and allow material and passengers in and out. Both breathe, pollute and need energy to function. Their functions within their respective domains are identical. This means that many of the relationships found in one domain will be found in the other, which  is why an equation formed in a metaphor is always expandable.

 

Eg: "Sugar is the fuel of the cell"; "Traffic flows quickly on major arteries". The evolution of the car has led from a metal shell to a tough flexible polymer shell, which closely resembles the material used in cell walls. Car alarms and keys have evolved to separate intruders from guests, matching systems used by cells to prevent unwanted foreign bodies from entering and taking over the cell. Fuel cell technology is closing in on the same proton exchange techniques used in all cells, and terms such as  "motor" are used in  biochemistry**** . The car is evolving to become even more cell-like, and new metaphors within this system will arise with each new cellular discovery or automotive invention. (It could be said that nanotechnology will be the meeting place of many, many metaphors).

 

[This website is dedicated to the proposal that the metaphorical relationships drawn between any  two disciplines are, in fact, universal, and therefore may be applied to extrapolate missing knowledge in all other disciplines.]

A short list of distinguishing characteristics:

"A metaphor is an equation where a simile is an approximation."

"A metaphor can always be greatly extended, while a simile quickly reaches its limits."

"The words like or as are widely known hallmarks of the simile - but there are so many faux similes bearing these hallmarks that further appraisal is always needed." 

"A metaphor dies of exhaustion; a simile just gets more and more tired."

J.D. Casnig

Take the "Difference Between Metaphor and Simile" Test!

 

Note: Both a metaphor and simile have a "tertium comparationis" or a third part that is being compared to. In the first example, the clouds and cotton candy are both soft and pleasurable; while in the second example the cars and cells are both independent means of transport. 

 

Both metaphor and simile rely on one's individual experiences. While the tertium comparationis for a simile appears to rely on the similarities between the author's and reader's individual valuations of these experiences (and is therefore vulnerable to differences in such things as culture or sentiment), the metaphor appears to rely on the similarities  between the author's and reader's individual understanding of these experiences (and is equally vulnerable to such things as differences in perspective or perception). Similes work most reliably where valuations are shared (where people feel the same), and metaphors work best where understandings are shared (where people think the same).

 

For example, the simile "Clouds like cotton candy" may stand to evoke an unintended sense of alarm in the mind of the diabetic, thereby destroying the intended "happy" message; while the metaphor "a car is a cell" may simply incite debate as to what a car or cell is, forcing an element-by-element comparison against accepted fact. In this way, the simile may be viewed as a somewhat intimate poetic device, and the metaphor viewed as a universal  poetic device.

 

Though some have argued that a simile is simply a weak metaphor, it is difficult prove with certainty in world of ambivalent usage. In the end, it may one day be determined that the difference between true metaphor and true simile may well be regional within the brain, with metaphor rooted in logic and the simile rooted in emotion.

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Notes

 

***Note: the cell in this case is a Paramecium, which powers its movement with hair-like whips, called cilia. If you feel you have paramecium in your bloodstream, please consult a physician.

 

****Note: This excerpt from the Biophysical Journal, shows the use of mechanical terms for energy transfer in a biochemical environment. Long before the auto was invented, its parts were being used naturally in all forms of life. Are these terms metaphors or simply statements of fact?

"They are mechanically coupled by a central rotary shaft and held together by a peripheral stator... By its rotary mechanism F₀  is distinguished from most other proton or cation transporters with the exception of the structurally unrelated ionic drive of the bacterial flagellar motor."

 

From the paper "The Proton-Driven Rotor of ATP Synthase: Ohmic Conductance (10 fS), and Absence of Voltage Gating", Biophysical Journal, Volume 86, June 2004, 4094-4109, by Boris A. Feniouk, Maria A. Kozlova, Dmitry A. Knorre, Dmitry A. Cherepanov, Armen Y. Mulkidjanian and Wolfgang Junge.

http://www.biologie.uni-osnabrueck.de/biophysik/junge/public/238.pdf

 

 

 

©Copyright J.D. Casnig