Yes, I know: I’ve used that title before.
Someone with an interest in psychoanalysis has asked me to explain the difference between Sigmund Freud and Jacques Lacan. Well as far as what they had to say is concerned there isn’t one really: Freud was a fine prose stylist, and (most of the time) he’s clear, straightforward, and easy to understand. Lacan said almost exactly the same things as Freud, but a) he said them a hundred years too late, and b) he said them with a bullshitting obscurity all too typical of twentieth-century French intellectuals.
If you want to understand psychoanalysis, read Freud. If you want to impress people, try to read Lacan. Here are pictures of the pair of them; take your pick:
By the way, I'm pretty sure Freud never really said that.