There was once a frog who had lived all his life in a well. One day a friend visited him and informed him of the existence of the Atlantic Ocean.
“Oh, what is this Atlantic Ocean?” asked the frog in the well.
“It is a vast body of water,” his friend replied.
“How vast? Is it double the size of this well?”
“Oh, no, much larger,” his friend replied.
“How much larger? Ten times the size?”
In this way the frog went on calculating. But what was the possibility of his ever understanding the depths and far reaches of the great ocean?
Our faculties, experience, and powers of speculation are always limited. The frog was always thinking in terms relative to his well. He had no power to think otherwise.
Similarly, the scientists are estimating the Absolute Truth, the cause of all causes, with their imperfect senses and minds, and thus they are bound to be bewildered. The essential fault of the so-called scientists is that they have adopted the inductive process to arrive at their conclusions. For example, if a scientist wants to determine whether or not man is mortal by the inductive process, he must study every man to try to discover if some or one of them may be immortal. The scientist says, “I cannot accept the proposition that all men are mortal. There may be some men who are immortal. I have not yet seen every man. Therefore how can I accept that man is mortal?” This is called the inductive process. He may study thousand, two thousand, five thousand, but he cannot study all the men. Therefore his conclusion remains always defective.
And the deductive process means you take the idea from superior person that man is mortal. Your father, your teacher, or your guru says that man is mortal, and you accept it.
If you accept, then your knowledge is perfect.
Therefore inductive process is not always perfect. The deductive process, from the authority, the knowledge received, is always perfect.
Ref :chapter 6, Science of Self Realization authored by Srila Prabhupada (Founder – Acharya, ISKCON)