Two very similar expressions yet quite opposite connotations. *Wise man* is an older phrase but *wise guy* is a newer one.

I found two possible connections to *wise man*. There is the surname *Wiseman* which is a long-established surname of Anglo-Saxon origin, and derives from the Olde English pre 7th Century "wys", meaning "wise", and "mann", a man, and was originally given as a nickname to a wise and learned man, perhaps one who was regularly consulted by other village inhabitants on matters pertaining to law or business transactions.1

*Wise men* is also mentioned as another name for *biblical magi* who were, in the Gospel of Matthew and Christian tradition, a group of distinguished foreigners who visited Jesus after his birth, bearing gifts of gold, frankincense and myrrh.2

Opposite connotations of the words from [*thefreedictionary*](http://www.thefreedictionary.com/wise+man):

> 
> *wise man*: a sage / a wise and trusted guide and advisor
> 
> 
> 
> 
> ---
> 
> 
> *wise guy:* a smart aleck / a person who is given to making conceited, sardonic, or insolent comments
> 
> 
> 

[Etymonline](http://www.etymonline.com/index.php?term=wise) says:

> 
> *Wise man* was in Old English. *Wise guy* is attested from 1896, American English...
> 
> 
> 

* How do these two phrases happen to have different connotations (one positive, other negative)?
* Is it possible to find an explanation regarding to their origins?

---

1 <http://www.surnamedb.com/Surname/Wiseman>   

2 <http://en.wikipedia.org/wiki/Biblical_Magi>