The Wadsworth collection is presented as an accessible guide to undergraduate students and general readers, with this version as an introduction to philosophers from the 15th century to the 18th century. The author does provide a background to each philosopher and how their upbringing influenced their thought, yet falls short of providing an approachable explanation of many of the thinkers covered.
The author presents the modern philosophical era in three phases, which increasingly become more complex in subject matter, yet the explanations become seemingly worse. While early chapters on Descartes and Locke are presented with clear introductions and examples the later chapters on Kant are filled with jargon and language more suited for a post-graduate level book than the introduction stated in the preface.
Yes, Kant and Hume are far more complex than Locke, but for the reader to follow the development of modern thought each chapter has to be equally accessible. One example is a passage summarizing Kant's thoughts on Metaphysics: "Science require transcendental idealism to explain the order in the world as expressed by synthetic a priori truths, it necessitates the negative concept of the noumenal" (page 185, Overall Conclusion)
I would not describe this as an accessible read. The language is too complex for the casual reader and the topics are too simple for those familiar with philosophy.