Tautologically Speaking...

I started reading Frye's second essay on the theory of symbols after class on Monday, with the subject of Tautology fresh on the brain. After our discussion about how this circular speaking is utilized by everyone from children trying to make reason, to the politicians we talked about in class, to GOD! We mentioned passages in the Bible that are tautological. I wonder if in an effort to express some ideas that are just too big to wrap the human mind around we can't help but resort to what ends up being repetition.
I think that literary criticism would be one such idea. Actually, when I was first getting into the theory of symbols, my initial thought was "Is this how you have to write in order to express a theory without a trace of tautology?" and, if so, what hope is there for the rest of us!
That was initially, as I read further I started to make note of some sentences that, within some very dense and meticulous passages, sound right repetitive... in Frye. For example, in "Literal and descriptive phases: symbol as motif and sign", I was a little stunned after reading this one:
"Poetic images do not state or point to anything, but, by pointing to eachother, they suggest or inform the mood that informs the poem" (Frye 81). Now, that sounds circular to me. But I'm sure a critic like Frye would never implore such a pathetic principle in his work.
Am I not getting the right idea of what Tautology is?
A wiki-search for the definition asks me to be a little more specific.... do I want to define tautology in regards to rhetoric or tautology in logic. I assume for our classes purposes, the rhetorical version. But just out of curiosity, what's the difference?
Tautology (rhetoric) is what we were making fun of Sarah Palin for in class- that is, the unecessary repetition of an idea; using different words to say the same thing twice. People who implore this rhetoric technique end up sounding either a)confusing, b) like children or c) like idiots. Rhetorical tautology can be logical if the sentence illustrates a truth, but it will usually be a completely useless assertions (wiki ex: "If you can't find it, you're not looking in the right place). Basically tautoloy in rhetoric is always going to be useless, senseless, or unecessary.
http://en.wikipedia.org/wiki/Tautology
As for tautology in logic- tautology that actually points to the truth and gets you somewhere.... that's a concept for the mathmeticians.