In the book, Youssef Karam discusses the existence of reason, the critique of reason, the problems of doubt and certainty, reason and metaphysics, truth and falsehood, the comparison between meaning and form, and his rejection of what the "sensualists" see as a denial of the existence of meanings and a reduction to the senses. He discusses the arguments of skeptics from the Greek philosophers to the present day and defends truth because the existence of error is evidence of the existence of truth. He also defends metaphysics, which is necessary because it is universal. Karam explains that his philosophical doctrine is characterized by certainty and faith. He believes that modern philosophies are sterile because they are devoid of reason, devoid of spirit, and devoid of faith.