  As a young man, Halevi had studied philosophy, and he continued to follow its evolution in Spain as newer Aristotelian ideas began to circulate among the courtier classes. However, his reactions to what he learned were decidedly mixed. As a trained physician, he certainly appreciated the high premium that the philosophers placed on careful observation and clear thinking. Lives were saved thanks to such skills or lost when they were lacking. He also admired the philosophers' achievements in the formal disciplines of logic and mathematics, inasmuch as they came as close to generating certainty as anyone could have hoped. Yet this achievement was also part of a larger problem. Halevi knew that since its inception philosophy had made the pursuit of truth in every domain its highest goal.  It persistently sought to distinguish between opinion and knowledge in order to replace opinions about all things with knowledge of all things. To the extent that this project could succeed, those able to acquire such knowledge, whether theoretical or practical, would presumably be of one mind about the truth they came to know and also live their lives in accordance with it. However, Halevi also came to realize that well before the goal is ever reached, opinions, conventions, and traditions of all kinds as well as the practices associated with them, would be rendered questionable or otherwise suspect, because they were not known philosophically to be true or right. A consequence of this demotion in status of everything unproved was that those best equipped intellectually to examine and judge such matters could, and often did, believe, or allow others to believe, that they had the requisite knowledge of exactly what others lacked by virtue of their mastery of logic, theory, and other intellectual skills. Whether, in fact, lovers of wisdom were also as wise as many of them or their proponents claimed seemed far from obvious to Halevi. But how could he even discuss such abstract issues in a work intended to vindicate the Jewish faith in a time of crisis? How, indeed, was he to give a reasoned account and defense of Judaism to his increasingly dispirited or doubting co-religionists, when the challenges came from so many different directions? Their detractors had the prestige of power, numbers, worldly success, and specialized new knowledge to support their claims, while the Jews had only their history, traditions, and what remained of their faith to fall back upon.