[Grammar] without as a conditional

[Swiss88]

In the sentence below, is "without" serving the same function that "If" usually does?

Life wouldn't be the same without good friends.


I was thinking it could be rewritten as


Life wouldn't be the same if we didn't have good friends.


So can we consider "without" as a conditional form?

Thanks!

 

[mmasny]

In this case, why not? But where's the condition in the following sentence?

He is a knight without a sword.