De libero arbitrio diatribe sive collatio

What it is

This is the title page of a book written by the humanist scholar Erasmus of Rotterdam, printed in Basel in 1524. In it Erasmus argues against Martin Luther's claim that human will is bound and that everything happens by necessity.

Why it matters

The book triggered one of the most important theological debates of the Reformation. Luther answered it with his own work, On the Bondage of the Will, which he considered one of his most important writings. The exchange shows how reformers and humanists who agreed on reforming the church could still disagree sharply on core theology.

Look closer

• What does the title page tell you about who printed the book and when?
• Why might Erasmus have chosen a calm, scholarly tone rather than an angry one?
• What does this debate reveal about disagreements even among reformers?