Darrell Pursiful has suggested these posts be cataloged (Thanks for the plug! I hope to get them published as a short guide too). So here are the posts in the series so far:
1. Faith, Evidence, and Biblical Scholarship
2. The Old Testament Canon
3. Genres in the Pentateuch
4. Critical Issues in the Pentateuch
5. Critical Issues in the Historical Books
As an illustration of my frustration with myself, I dug up a copy of Ronald Clements' 1976 book A Century of Old Testament Study to help me with some OT issues. I think it was one of a few books I took to Sierra Leone, West Africa, when I was there for a couple months in the winter of 97 (not a great time to be in the country, if you remember what happened there in the spring). Typical of me, I noticed this afternoon that I have underlined things throughout the book.
I remember none of it.
Strangely, it was apparently not until the time of Robert Lowth (1710-87) that anyone seems to have pointed out the secret to understanding Hebrew poetry. You will notice, for example, that the King James Version of 1611 and even the current revision of 1769 do not have the Psalms or relevant passages of the Prophets in poetic form, as most modern translations do. While stereotypical poetry in recent centuries rhymes sounds, and while classical ancient Greek and Latin poetry followed a certain meter, ancient Hebrew poetry "rhymed" thought.
The secret to Hebrew poetry is thus parallelism, "say it; say it again" or "say it; say the opposite." Although various scholars have proposed refinements on the various categories of parallelism, the simplest categorization admits of three basic types.
Synonymous parallelism is of the type, "say it; say it again."
"Create in me a clean heart, O God,
And renew a right spirit within me.
"Cast me not away from your presence,
And do not take your Holy Spirit from me" (Ps. 51:10-11).
In the lines above, you can see that the second line in each stanza "rhymes" or parallels the thought of the first in a roughly synonymous way. Recognizing the generally synonymous nature of parallel lines can be a great help in interpretation.
Antithetical parallelism is of the type, "say it; say the opposite."
"The fear of the LORD is the beginning of knowledge;
Fools despise wisdom and instruction" (Prov. 1:7).
In this case, the second line says roughly the opposite of the first. We can thus possibly infer that a "fool" here is not a stupid or ignorant person but a person whose attitude toward God is wrong.
Synthetic parallelism was the category into which Lowth lumped other instances of Hebrew poetry that neither were roughly synonymous or antithetical. In many such instances the next line or lines extend the thought.
"Know that the LORD,
He is God!
It is He who has made us,
And we are His.
We are His people,
And the sheep of His pasture" (Ps. 100:3).
Notice how each line seems to extend or in some cases complete the thought of the line before.
Various subcategories of the above are often mentioned (e.g., step parallelism, introverted parallelism, etc.). Such categorizations are far more meaningful to us as catgorizers than helpful in interpretation. They are categorizations of form that describe the artfulness of the text but do not contribute much to our understanding of meaning. The general breakdown into three general headings seems sufficient for us to know how to interpret Hebrew poetry.