Jesus the logician?

Joe Carter is attempting to inaugurate a blogging project. In his words:

I offer the following as a project to be tackled by my fellow faithbloggers: the creation of comprehensive database outlining the ways in which Jesus used logic in his discourses.

Carter quotes extensively from Dallas Willard, who has a high view of Jesus's use of logical discourse and argumentation. Why shouldn't he? As Douglas Groothuis writes,

For all their honesty in recording the foibles of the disciples, the Gospel writers never narrated a situation in which Jesus was intellectually stymied or bettered in an argument; neither did Jesus ever encourage an irrational or ill-informed faith on the part of his disciples.

But wait. Let's parse the first claim: generally speaking, why would the Gospel writers want to show Jesus's foibles? (His disciples, foolish as they sometimes seem, are perfect foils for Jesus, literarily speaking.) There may have been situations where Jesus was in fact stymied, or took a long time thinking up an answer, that just aren't included. (If we think the Gospels are a "fair and balanced" presentation of Jesus's career and teachings, we assume too much.)

Jesus, no doubt, is a master of rhetoric. But rhetoric sometimes comes at the expense of logic. Even within the Gospels one can find examples of sloppy reasoning and obfuscation, many (if not most) in John, chief among the Gospels for its oracular density and maddening repetitiveness. I'll point out just a few examples.

First, look at Jesus's defense of his authority in the book of John, specifically chapters 5 and 8.
Jesus examines what constitutes valid evidence for a claim. First, he states,

"If I testify about myself, my testimony is not valid. There is another who testifies in my favor, and I know that his testimony about me is valid."

Seems fair enough; trumpeting one's own accomplishments is a pretty poor way to gain credibility. But three chapters later,

The Pharisees challenged him, "Here you are, appearing as your own witness; your testimony is not valid."

Jesus answered, "Even if I testify on my own behalf, my testimony is valid, for I know where I came from and where I am going. But you have no idea where I come from or where I am going. You judge by human standards; I pass judgment on no one. But if I do judge, my decisions are right, because I am not alone. I stand with the Father, who sent me. In your own Law it is written that the testimony of two men is valid. I am one who testifies for myself; my other witness is the Father, who sent me."

In John, Jesus sounds very much like Walt Whitman. "Do I contradict myself? / Very well then, I contradict myself, / (I am large, I contain multitudes.)"

In Matthew 15 (paralleled in Mark 7 ), contra Groothuis, Jesus actually is bested in an argument.

Leaving that place, Jesus withdrew to the region of Tyre and Sidon. A Canaanite woman from that vicinity came to him, crying out, “Lord, Son of David, have mercy on me! My daughter is suffering terribly from demon possession.”

Jesus did not answer a word. So his disciples came to him and urged him, “Send her away, for she keeps crying out after us.”

He answered, “I was sent only to the lost sheep of Israel.”

The woman came and knelt before him. “Lord, help me!” she said.

He replied, “It is not right to take the children's bread and toss it to their dogs.”

“Yes, Lord,” she said, “but even the dogs eat the crumbs that fall from their masters' table.”

Then Jesus answered, “Woman, you have great faith! Your request is granted.” And her daughter was healed from that very hour.

(We may speculate as to why Mark's rendering doesn't include the line "I was sent only to the lost sheep of Israel," and makes no mention of "faith," and why Luke's Gospel entirely omits the story.)

Other logical fallacies are there for the finding. There's petitio principii, John 8:43:

Why is my language not clear to you? Because you are unable to hear what I say.

Denying the Antecedent, John 8:47:

He who belongs to God hears what God says. The reason that you do not hear is that you do not belong to God.

To sum up: there is no need to deny Jesus his greatness as an orator and profound thinker. But his logic is not perfect. In that respect, he's just like the rest of us.