The Voice of Reason: Essays in Objectivist Thought is a collection of essays by Ayn Rand, Leonard Peikoff, and Peter Schwartz, and edited by Leonard Peikoff. It appeared in 1989.
The essays by Rand originally appeared in a variety of places, including Rand's newspaper column and in The Objectivist Newsletter, The Objectivist, The Ayn Rand Letter, and The Objectivist Forum.
The essays by Peikoff are based on his talks at the Ford Hall Forum in Boston, which he carried on after Rand. Schwartz's essay is an expanded version of an article in The Intellectual Activist.
This book is volume five of the "Ayn Rand Library" series edited by Peikoff.

Introduction to Objectivist Epistemology

Today man's mind is under attack by all the leading schools of philosophy. We are told that we cannot trust our senses, that logic is arbitrary, that concepts have no basis in reality. Ayn Rand opposes that torrent of nihilism, and she provides the alternative in this eloquent presentation of the essential nature--and power--of man's conceptual faculty. She offers a startlingly original solution to the problem that brought about the collapse of modern philosophy: the problem of universals.