Voltaire was 72 years old in 1766 when The Ignorant Philosopher was published, a mischievous invitation to a journey around the world of philosophy. Mocking Descartes, Spinoza and Leibniz – the will is no more free than it is blue or square, he opposes the first –, praising the analyzes of Pierre Bayle and John Locke, Voltaire criticizes above all the systematic spirit of philosophers, which lies in wait for the failings of his Pangloss. Unlike them, the ignorant philosopher Voltaire does not hide his contradictions: yes, one can be both a deist and deeply skeptical; yes, we can maintain that the principles of morality, like all ideas, are acquired through the senses, and nevertheless affirm that there exists a universal and natural morality founded in God. For the ignorant philosopher never ceases to seek the truth. This is the self-portrait that Voltaire gives us here.