One major theme is the search for wisdom. Seeking wisdom is akin to loving one's soul. Wisdom is portrayed as a woman calling out in the public square. She was born at the creation of the earth, and leads to riches and honor. One must approach study with humility. Appropriately, the Book of Proverbs is considered an example of wisdom literature. Famously, it is said here that the fear of the Lord is the beginning of wisdom.
In fact, I would say the paramount virtue, according to this book, is humility. Everything else in the text comes from that.I also find fascinating the idea that foolishness is literally life-threatening. The fool is not just mistaken or silly here; they're actually tending towards death, and so their company must be avoided at all costs. ''As a dog returns to his vomit, so does a fool repeat his folly''. My first thought would be to simply correct a fool, but I think this book is intended for a young person who hasn't the knowledge yet to correct anyone.
A second theme is discipline, which is seen as the first step towards knowledge. There are proverbs making the age-old point that a man who plows his fields in the winter has food in the next year. The son should accept the discipline of the father. Humility is good also- before honor there is humility. One should accept the council of a wise man as well as his criticisms. Haughtiness is an abomination. The father who fails to discipline his son hates him.
A third theme is to avoid the company of bad people. Forsake the foolish and avoid scorners. Do not take up with thieves or wicked people. Do not associate with immoral or strange women- their words are sweet like honey, but the aftertaste is like wormwood. Harlots lead men to death, calling to them in a parallel to the way Wisdom is a women calling to them. Adultery, of course, is forbidden. Harlots occur frequently here, leading me again to think this is intended as a father's advice to his son. Interestingly enough though, there are warnings about both harlots and foreign women. I think context is important for understanding what threat foreign women posed.
Violent or scornful people should also be avoided. Do not quarrel without cause and do not imitate a man of violence. Do not have violence in your own heart. A quarrelsome wife is a curse. He who is slow to anger is of great understanding. One who conquers himself is greater than he who conquers a city. Again, these seem like proverbs most suited to an adolescent male.
Charity is important. He who favors a poor man honors the Lord, but he who oppresses a poor man offends the Lord. Being gracious to a poor man is like lending to the Lord and will be repaid by the Lord. It's complex though, because a lazy man will become impoverished, which may well explain why so many religious people seem to feel secure in giving very little to the poor. But social justice is a major theme here, and I would imagine it's arrogance to scorn or avoid the poor. From what I've read of these books- the Torah, the Bible, and the Koran- I'd think that if I was a believer, I'd be tithing like crazy.
Another theme is the dangers of speech. The mouth of the foolish man pours out dangerous words- there are quite a few metaphors here about honey or water flowing from the mouth. The fool's mouth is his snare. An evildoer hearkens to the language of violence. The wise man is often silent. He who has knowledge keeps back his words. This reminded me of the parable of Jesus and the Grand Inquisitor in The Brothers Karama. But pleasant words are healing. There is a sense that the words of a wise man are a balm and an incentive to learning. Again, the company you keep is important here.
Overall, there isn't much here that strikes me as bizarre or wrongheaded, like in some other books of the Old Testament. It's hard for me to imagine what they mean about these harlots who roam the streets looking to bring men to death- although given the time, this could refer to prostitutes and thieves as easily as to wanton women. And there are bits of prophecy towards the end that are a bit confusing. What the book reminds me of more than anything is Confucius, in that it tends towards vague suggestions as to the character of a good or bad person, as opposed to laying out clear-cut rules. In that, I think there is much room for interpretation here.