Frederick Copleston's original nine-volume A History of Philosophy began as an attempt to provide Catholic seminary students, whom Copleston believed were being woefully undersold in philosophy, a comprehensive but accessible guide to the ideas and individuals that have shaped philosophy. His work went on to be regarded by many a single best history of philosophy ever written in English.
Coplsteon's work sought provides a detailed, and by consensus fair, treatment of the major philosophers and their ideas from the Pre-Socratics all the way up to Levi-Strauss. He skillfully avoids simplistic caricatures and his narrative sparkles with incident and intellectual excitement giving each philosopher a full hearing with erudition, attention to style, while illuminating each figure has to those who came before and to those who came after.
Nevertheless Copleston, who is well known for his public debates and resounding defenses for the existence of God, never hides his own perspectives--but he also does not use it to truncate or distort others' views. Thus, Copleston's work is remarkably well-rounded, complete, and scholarly. Though originally intended for students, Copleston's work is a staple work for any library; especially those who wish to learn about and engage philosophical questions in an informed manner.
About Volume IV A History of Philosophy, Volume IV: Modern Philosophy From Descartes to Leibniz begins with a magnificent treat: a 62 page essay introducing readers to Modern Philosophy (Descartes to Kant) generally, and to Volumes IV, V, and VI (covering from ) in Copleston's nine volume effort. Following this essay, Copleston dives straight ahead into Descartes and his initial turn to the 'I' and then follows by examining Pascal, the rise of 'Cartesianism', followed by treatments of Malebranche, Spinoza, and the pivotal Leibniz.