A research student wrote a thesis paper about a fly.
He extracted one leg from the fly and asked the fly to jump from one hand to the other. The fly jumped. (Insect lovers, please bear with me for a moment.) He removed the second leg and repeated the command. The fly jumped again. He pulled out the third leg and told the fly to jump. Once more, the fly jumped. He yanked out the final leg and commanded the fly to jump one more time.
This time the fly did not jump. The student promptly wrote down his conclusion: When you pull out all four of a fly’s legs, it loses its hearing.
A deduction based on false assumptions leads to an invalid conclusion, and we simply cannot base conclusions on impeded judgments or limited assumptions. — Ravi Zacharias