In 1756 a volume of Hume's essays entitled Five Dissertations was printed and ready for distribution. The essays included "The Natural History of Religion", "Of the Passions", "Of Tragedy", "Of Suicide", and "Of the Immortality of the Soul". The latter two essays made direct attacks on common religious doctrines by defending a person's moral right to commit suicide and by criticizing the idea of life after death. Early copies were passed around, and someone of influence threatened to prosecute Hume's publisher if the book was distributed as is. The printed copies of Five Dissertations were then physically altered, with a new essay "Of the Standard of Taste" inserted in place of the two removed essays. Hume also took this opportunity to alter two particularly offending paragraphs in the Natural History. The essays were then bound with the new title Four Dissertations and distributed in January, 1757.

The essays in Four stand together as a unified whole, showcasing his psychology of the passions and demonstrating its application to both religion and aesthetics.

This edition also includes Hume's extended Dedication, a passionate endorsement of intellectual and artistic freedom, which has been out of print since the original publication in 1757.

The essays on suicide and the immortality of the soul, long separated from the other essays, are here finally put back, as intended by Hume. "On the Immortality of the Soul" briskly dismisses metaphysical, moral, and physical arguments, and refers us instead to a revelation that Hume himself clearly did not believe in. "On Suicide" vigorously rebuts the theologians' claim that self-destruction is a crime, arguing instead that under certaincircumstances, suicide might be not permissible but morally required.

Included are "Two Letters on Suicide" from Rousseau's Eloisa.