Book excerpt: Enlightenment—Aufklärung in German, Lumières in French—is more an idea than a period. But it is an idea that took hold in a particular historical context of revolutionary scientific advances, increasing economic and social freedom, rising literacy and prosperity, and a greater willingness to challenge the authoritarianism of the seventeenth and eighteenth centuries. In The Wisdom of the Enlightenment, author Michael K. Kellogg points to 1637, the year that gave us Rene Descartes’ landmark inquiry into truth, as the beginning of a period that radically changed individual human thought and collective societal action. From Descartes’ assertion of “I think, therefore I am,” to the philosophies of Enlightenment thinkers like Moliere, Spinoza, Voltaire, Hume, and Kant, this book charts the new and revolutionary philosophies at a time when progress seemed possible across the whole range of human knowledge and endeavor. In sweeping aside tired superstitions and applying a new scientific methodology, the Enlightenment ideas of progress through free exercise of reason ushered us into the modern world. This engaging and comprehensive survey of Enlightenment thoughts and thinkers is a celebration of the faith that all problems are solvable by human reason. ,