In the White Russian province of Mohilev lived a humble Jew, a Chasid of Rabbi Shneur Zalman, the first Rebbe of Chabad-Lubavitch. The Chasid had a son who was an exceptional child from the day he was born. It was almost eerie the way the boy absorbed information; seeing or hearing something only once was enough to imprint it in his memory forever.
The first time his father showed him the alef-beit it was already mastered. But the most amazing thing was how the toddler was able to put them together and read. The most complex philosophical concepts were comprehended at once. The boy was a phenomenal genius.
His parents, fearful of an "evil eye," were afraid to send him to cheder. A private tutor was hired, but he was rapidly outpaced. By the age of Bar Mitzva the boy was an experienced swimmer in the sea of Talmudic wisdom, and he steadily climbed the ladder of knowledge.
One day the father walked into his son's room and saw him reading a small pamphlet. His blood ran cold as he realized it was a treatise designed to lure unsuspecting yeshiva boys into the net of the Enlightenment.
"Why do you need to search in foreign pastures?" he scolded him. "The entire Torah is yours, the true source of G-dly wisdom. There is nothing to be gained by looking elsewhere."
"You are right, Father," the boy apologized. "I found it lying in the street, and at first it didn't interest me. The only reason I was glancing through it now was to see for myself how groundless are their arguments."
The father wasn't entirely convinced, but preferred to delude himself.
Over the next few weeks and months the boy was caught several more times. He was silent when confronted, and would not deny that the Enlightenment had captured his heart. Eventually he left home, after calling his father "an idiot" for his religious convictions. His destination was Berlin, the seat of the Enlightenment.
In Berlin, the Academy of Sciences received him with open arms. In no time at all he distinguished himself with his phenomenal intellectual abilities. His rise through the ranks of academia was steady and swift. After several years in Germany he went on to study in Paris.
The young man was particularly interested in mathematics and medicine, and he decided to write a book on each of them. The mathematical treatise dealt with an original theorem he had formulated, the other book was on the subject of anatomy. Soon he was the darling of the international scientific community.
Inexplicably, however, he began to feel guilty over how he had treated his parents. He took a leave of absence and set out for home.
The long journey gave him time to think. "What good will it do to show my father my books?" he mused. "He has no understanding of such matters. Better I should first go to my father's Rebbe and get his approval. They say that as a young man, Rabbi Shneur Zalman studied geometry and astronomy. If he pronounces them worthy, my father will respect his opinion."
Rabbi Shneur Zalman agreed to see him at once. The Rebbe's door was closed for a long time. When the young man finally emerged he was extremely agitated. It was obvious he was in the midst of an inner battle.
Suddenly, without warning, he grabbed one of his books and threw it into the furnace. A minute later the second one followed. Both were quickly consumed by the flames. Only then did he calm down.
What had happened? Rabbi Shneur Zalman had scrutinized only five pages of the first book when he drew a line through several paragraphs. After leafing through the rest, he pronounced the reasoning sound. "But unfortunately, the book is based on an error in calculation at the very beginning. As the foundation is faulty, the rest of the edifice is also flawed."
The same happened with the next book. The Rebbe pointed out a sentence that contradicted what the Torah says about a certain juncture of veins. "As our Sages are undoubtedly right, the entire treatise is based on an untruth."
The young man was in a mental turmoil, but eventually had to admit that the mistakes were his. He felt he had no choice but to destroy the books.
The young man began to study with Rabbi Shneur Zalman. Seven weeks later he fell ill, and a short time after that passed away.
Rabbi Shneur Zalman later revealed that the young man was a reincarnation of Rabbi Eliezer ben Durdia. His soul had already descended into the world several times, each time following the same progression: As a young man it would faithfully observe Torah and mitzvot, but as time passed it invariably left the straight and narrow. "This time, when he came to me, I decided that enough was enough. I refused to let him leave until his soul had accomplished its final tikun (correction)."
(Incidentally, Rabbi Shneur Zalman gave his son, the Mitteler Rebbe, the manuscripts of everything he had learned with the young man. It was based on these writings that he authored his work, Derech Chaim.)