Well, there are those (and there are MANY MORE) who would state that not only did Jesus exist - without a doubt, but he's GOD, too.
Did a man exist that said those things?
Probably.
Was he even necessarily named Jesus?
We could call him "Bob the Savior" and it might be just as valid a name. Of course, did he do the whole laundry list of things *for real* as some would like me to believe? Probably not.
Similarly, with or without a literal Socrates, the words were said and written by *someone*. Call him or her "Bruce the Philospher", if you like.
So "Bruce the Philospher", or Socrates or whatever probably wrote or said some of that stuff. Also quite possibly, in the same way that email chain letters get "famous" names tacked on to gain more milage from drivel, some nerds over time have probably takcked the "Socrates" name onto their own "quotes".
Naturally, the same applies to "Jesus". As an example, some dork liked the sound of "Give Caesar what is his" (wherever that phrase came from), and it got Jesus's name stuck on it. When you consider that Christianity was adopted by the Roman Empire as its "standard", a little jot from the powers that be to encourage people to pay their taxes obviously can't hurt any.