The sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneersohn, was once challenged: “Tell me, Rebbe, how can you, in this day and age, still insist that the Torah is the unadulterated word of G‑d? Are you not the least bit swayed by the fact that so many Bible critics and men of science reject your beliefs?”

The rebbe responded with a story:

A young aspiring inventor labored for many years on a project. Finally, he wrote to his mentor, a great engineer under whose tutelage he had studied, saying that he wished to present his efforts for his teacher’s critique. The great engineer replied that he was scheduled to be in the young man’s hometown in a few weeks, and that he would be more than happy to drop by and offer his comments on his beloved student’s invention.

As the appointed day neared, the young man grew extremely agitated. He felt that this was to be the most important test of his career. He saw this invention as the embodiment of his most creative ideas; his mentor’s opinion of it would be the ultimate assessment of his worth.

When he woke that morning, he knew that he could not trust himself to face his mentor’s verdict. He left his blueprint on the table of his study, together with a note in which he begged forgiveness for his absence and asked his teacher to please put his comments in writing. After telling his wife to direct the engineer to the study, he left the house to pace the streets.

It was late in the evening when he re-entered his study. No sooner did his glance fall on the table than he uttered a small cry and collapsed in his chair. His wife, rushing to her husband’s side, found him white as a sheet and with a look of utter despair in his eyes. On the table lay the blueprint of his invention, with a few terse lines of black ink crisscrossing it from corner to corner.

“It does look like it’s in bad shape,” said his wife. “But can’t you redraw it from memory?”

“Draw it from memory? Every line on that diagram is ingrained in my mind. I can draw it in my sleep. But that is hardly the problem, is it?”

“What then is the problem?” wondered the good woman.

“The problem is that the greatest engineer in the land has crossed out the last ten years of my life!”

“Your teacher?” said the inventor’s wife. “He sent word that he can’t come today. What happened was that the cat climbed onto your table and knocked over a bottle of ink.”