Introduction and Authorship
The Book of Ecclesiastes is one of the wisdom books of the Old Testament, traditionally attributed to King Solomon. The Hebrew title, "Qoheleth," is often translated as "Teacher" or "Preacher," and the book is known for its exploration of the meaning of life and the human experience. The opening verse, "The words of the Teacher, son of David, king in Jerusalem" (Ecclesiastes 1:1), suggests Solomonic authorship, although some scholars debate this due to linguistic and stylistic considerations.

Structure and Content
Ecclesiastes is composed of twelve chapters, presenting a series of reflections and observations on life. The book is characterized by its philosophical tone and the repeated refrain "Vanity of vanities, says the Teacher, vanity of vanities! All is vanity" (Ecclesiastes 1:2). This theme of "vanity" or "meaninglessness" underscores the transient nature of worldly pursuits and human endeavors.

The book can be divided into several sections:

1. The Futility of Human Effort (Chapters 1-2): The Teacher examines various pursuits—wisdom, pleasure, work—and concludes that they are ultimately futile. "I have seen all the works that are done under the sun, and indeed, all is vanity and a chasing after the wind" (Ecclesiastes 1:14).

2. The Cycles of Life (Chapter 3): This chapter famously begins with a poetic reflection on the seasons and times of life, "To everything there is a season, and a time for every purpose under heaven" (Ecclesiastes 3:1). It emphasizes the inevitability of life's cycles and the limitations of human control.

3. The Injustice and Uncertainty of Life (Chapters 4-6): The Teacher observes the prevalence of oppression, envy, and the unpredictability of wealth and success. He notes, "Again, I saw all the oppressions that are done under the sun" (Ecclesiastes 4:1).

4. Wisdom and Folly (Chapters 7-8): These chapters contrast wisdom and folly, acknowledging the value of wisdom while recognizing its limitations. "Wisdom, like an inheritance, is a good thing and benefits those who see the sun" (Ecclesiastes 7:11).

5. The Uncertainty of the Future (Chapters 9-11): The Teacher reflects on the unpredictability of life and the certainty of death, urging readers to enjoy life while they can. "Go, eat your bread with joy, and drink your wine with a merry heart, for God has already approved your works" (Ecclesiastes 9:7).

6. The Conclusion of the Matter (Chapter 12): The book concludes with a call to remember the Creator in one's youth and a final exhortation: "Fear God and keep His commandments, for this is the whole duty of man" (Ecclesiastes 12:13).

Theological Themes
Ecclesiastes grapples with profound questions about the meaning of life, the limits of human understanding, and the role of God in the world. It acknowledges the apparent futility of life "under the sun" while ultimately pointing to a life lived in reverence to God as the source of true meaning. The book's exploration of existential themes resonates with the human experience, offering a sobering yet hopeful perspective on life's complexities.

Canonical Status and Influence
Ecclesiastes is part of the Ketuvim, or Writings, in the Hebrew Bible and is included in the Christian Old Testament. Its candid exploration of life's enigmas has made it a subject of much theological reflection and debate. Despite its seemingly pessimistic tone, Ecclesiastes has been valued for its honest appraisal of the human condition and its ultimate affirmation of faith in God.