A couple of times in this series on the Chicago Statement on Biblical Inerrancy I've mentioned poetry in the Bible and I'd like to deal with this question a little more fully.
Article VI of the Chicago Statement on Biblical Hermeneutics says
WE AFFIRM that the Bible expresses God's truth in propositional statements, and we declare that biblical truth is both objective and absolute.
The problem with this affirmation is that it is simply and clearly wrong for large parts of the Bible. Even the framers of the Statement on Inerrancy recognised this, saying in Article XVIII
WE AFFIRM that the text of Scripture is to be interpreted by grammatico-historical exegesis, taking account of its literary forms and devices....
They knew this to be the case, but they obviously didn't know what to do with it, or they couldn't have put their article about "propositional truth" in the follow-up statement.
So what's propositional truth? Mr Google defines it as follows.
Truth which can be communicated in the form of a statement in which a predicate or object is affirmed or denied regarding a subject.
In other words, if I say "right now I'm writing on my blog", then I'm affirming the predicate (writing on the blog) about the subject (myself). This statement is objectively verifiable - my wife could come into the room and would see that I'm writing my blog. It is either true or false - either I'm writing my blog or I'm not.
Some of the Bible is certainly like this. When Paul says (in Romans 8:1), "Therefore, there is now no condemnation for those who are in Christ Jesus", this is a propositional statement. It's much more complex than the one about my act of writing, and there's lots of terms in it we would need to define carefully, but in theory it's the same kind of statement.
However, large parts of the Bible aren't like this. In particular, a lot of the Old Testament is poetry - not only the Psalms, Song of Solomon and Job, but also large slabs of the prophets are written in poetic form. In addition, books like Daniel, Ezekiel and Revelation are allegorical (in whole or in part), and of course Jesus spoke in parables. These forms of writing do not contain propositional statements, they contain metaphors, symbols, images, hyperbole, personification - the whole range of tricks of the trade.
For example, take a look at Psalm 57.
Have mercy on me, my God, have mercy on me,
for in you I take refuge.
I will take refuge in the shadow of your wings
until the disaster has passed.
I cry out to God Most High,
to God, who vindicates me.
He sends from heaven and saves me,
rebuking those who hotly pursue me
God sends forth his love and his faithfulness.
I am in the midst of lions;
I am forced to dwell among ravenous beasts—
men whose teeth are spears and arrows,
whose tongues are sharp swords.
Be exalted, O God, above the heavens;
let your glory be over all the earth.
They spread a net for my feet—
I was bowed down in distress.
They dug a pit in my path—
but they have fallen into it themselves.
My heart, O God, is steadfast,
my heart is steadfast;
I will sing and make music.
Awake, my soul!
Awake, harp and lyre!
I will awaken the dawn.
I will praise you, Lord, among the nations;
I will sing of you among the peoples.
For great is your love, reaching to the heavens;
your faithfulness reaches to the skies.
Almost nothing in this song makes sense if you try to treat it as propositional truth. Of course there are the obvious things - he is not surrounded by lions, these are a metaphor for people who want to kill him. There are not literal nets or pits in his way - he just means people are trying to trap him. But there's more to it than that. For instance, look at the way he talks about love. "God sends forth his love and his faithfulness". These are not substances or beings that can be sent anywhere, they are actions. What can this mean? And at the end he says "great is your love, reaching to the heavens". How does love reach up? And what does he mean by saying "in you I take refuge"? How can someone be "in" God?
The thing is, we know what he means, He is celebrating how loving God is, and how God cares for him in the midst of troubles. He uses a wide array of poetic tricks to make his point. Those of us who have faith believe this to be true. But it doesn't make any sense to talk about it as "inerrant" because it doesn't have that kind of precision.
You could try to say that you will interpret this "taking account of its literary forms and devices" - so you would recognise it as a poem, not try to insist on the literal truth of the images, and instead insist on the truth of the statement - God is loving, and protects his people or his king. This statement (assuming you have interpreted correctly) is what is inerrant.
This is fair enough as far as it goes, but to say this is to miss the point. Why did David write a poem, with all this flowery language, when he could have just said it in one sentence and been a lot clearer? It's because the central point of a poem or a song is not the "propositional truth" it expresses, it is the emotional impact of that truth. David doesn't just want us to nod and say, "yes, that's objectively true". He wants this truth to be subjective. He wants us to feel his agony and fear, to feel his relief at knowing God rescues him, to feel the sense of safety and protection of a chick being guarded by its mother hen. He wants the temple singers to sing this so beautifully that the gathered worshippers leave with tears in their eyes at the depth of the love of God.
This is not inerrant. It is so much more than that.