analogy n. 

1. Corresponding in some respects, especially in function or position, between things otherwise dissimilar. 
2. A form of logical inference, or an instance of it, based on the assumption that if two things are known to be alike in some respects, then they must be alike in other respects.

 
"Differences are more important than similarities."
-- Paul Niquette

Well-intentioned parallels can become intellectual traps.  At the least, a person who resorts to them must accept the solemn responsibility for validating all aspects of the comparison: technical factors, economic issues, and human considerations.  Otherwise, the analogy is meaningless or worse, misleading.   Here's why:  Differences are more important than similarities.

That might not be an inviolate law of nature, but just try to find exceptions to it.  Consider the word pairs:

• interest versus curiosity,
• innocence versus naivete,
• depth versus brilliance,
• distinguished versus conspicuous,
• liberal versus libertarian,
• conservative versus conservationist,
• distinction versus differentiation,
• values versus beliefs,
• intellect versus intelligence,
• intelligence versus knowledge,
• knowledge versus intellect,
• rationality versus rationalization (the mind's best hope versus the ego's worst mischief).

Ah! you ask:  What then is "experience"?  Is it not in some sense the accumulation of analogous cases?  For many, the answer must be yes.  And for them, experience is surely not the best teacher.  What Samuel Taylor Coleridge said more than 150 years ago may well apply (even though he drew upon an analogy):

"If men could learn from history, what lessons it might teach us!  But passion and party blind our eyes, and the light which experience gives is a lantern on the stern, which shines only on the waves behind us!"

Hey, Coleridge.  Why not hang the "lantern" on the bow?

Watch out for "passion and party" there, Sam.

As for me, I will not invoke an analogy except to illustrate an agreed-upon point.

Even then, I prefer to create a metaphor ("painting the walls while the plaster is still wet") or a simile ("as fickle as a day-trader in pork-belly futures").