One way of beginning an article or talk is by making a profession of humility. We'll call this a CB for short. Adeptly handled, this technique presents the speaking self of the article or book chapter as attractively modest, but without undercutting his or her authority. In other words, the audience understands that it is being seduced by the profession of modesty, but also understands that the modesty is a rhetorical device. There is an article by Derrida in The Translation Studies Reader (ed Venuti) that was originally a talk given to a professional association of translators. Derrida goes on and on at the beginning about how unqualified he is; he knows less about the subject (translation) than his own audience. Yet this CB does nothing, ultimately, to undercut his actual talk. Once he get into his main points he leaves behind this posture of modesty completely. Derrida is not a modest writer in the least.
I've seen people completely undercut their own authority by apologizing in a way that makes the audience think, "hey, he doesn't really know what he's talking about."
The paradox, then, is that the CB must be performed arrogantly enough so that it is transparently false. It must not be taken literally, but as a rhetorical ploy.
The Socratic dialogue is based on a profession of ignorance, but Socrates uses that ignorance (known as Socratic irony) as a form of rhetorical jujitsu, lulling his interlocutors into thinking he is going to be easy to debate. The CB is also rhetorical jujitsu. It's got to be performed from a stance of strength, not weakness.