An Enquiry Concerning Human Understanding is a book by the Scottish empiricist philosopher David Hume. This book has proven highly influential, both in the years that would immediately follow and today. Immanuel Kant points to it as the book which woke him from his self-described "dogmatic slumber".

The argument of the Enquiry proceeds by a series of incremental steps, separated into chapters which logically succeed one another. After expounding his epistemology, Hume explains how to apply his principles to specific topics.

I. Of the Different Species of Philosophy

II. Of the Origin of Ideas

III. Of the Association of Ideas

IV. Sceptical Doubts Concerning the Operations of the Understanding

V. Sceptical Solution of these Doubts

VI. Of Probability

VII. Of the Idea of Necessary Connexion

VIII. Of Liberty and Necessity

IX. Of the Reason of Animals

X. Of Miracles

XI. Of a Particular Providence and of a Future State

XII. Of the Academical or Sceptical Philosophy