Before Shankaracharya came to this world, there were many different philosophies. The scriptures were interpreted in different ways. Some books, which were not scriptures e.g. Manusmriti, were being studied.
Shankaracharya traveled all over India. He debated with other scholars and defeated them. He established his version of Truth.
Even though there are more than 100 Upanishads, Shankaracharya considered most of them irrelevant. He wrote commentaries on a few of them. He told his disciples to concentrate on the study of these Upanishads only.
Now, note that Shankaracharya didn't use any scientific method to prove that most of the Upanishads were wrong. He said, "I know the Truth. These Upanishads are wrong and these are right."
The Upanishads are written in a very cryptic form i.e. A good book has lots of diagrams and many examples. The Upanishads contain no diagrams and most don't have any example. So the same verse of an Upanishad can be interpreted differently by different scholars.
Shankaracharya never proved scientifically why only his interpretation of Upanishad was correct. Again, he effectively said, "I know the Truth. This is how this verse should be interpreted."
Shankaracharya also wrote a commentary on Gita. In Gita, Krishna says to Arjuna, "Karma yoga is better than Jnana yoga." Shankaracharya, in his commentary, says "Jnana yoga is better than Karma yoga."
So when Scriptures say something that Shankaracharya disagrees with, he effectively says, "I know the Truth. This verse in the Scriptures is incorrect. The real meaning of the verse is exactly opposite of what the verse says."
Shankaracharya summarized his teaching in the book Vivekchoodamani. Many of his directives, from this book, can be questioned.
He says, "A disciple should go to a Guru, serve the Guru and learn from him". In the days of Shankaracharya, Internet didn't exist. Students used to go to a Teacher's home and study. Today, students can study at their homes. So is this directive of Shankaracharya still meaningful?
He says, "First purify yourself with Karma yoga. Then take Sanyasa. Then meditate." He never scientifically proves why this sequence is mandatory for everyone. Why can't someone meditate daily living a normal life? What happens if someone meditates without taking Sanyasa? Does the fruit of meditation differ based on external activities/appearance?
Shankaracharya claims that an experience in meditation (Realization of Truth) is perfection for humans. This is again questionable because
Essentially, Shankaracharya says, "I Know the Truth. I will tell you the way. You just follow it. Have faith in me."
If a doctor were to say, "I know this medicine works. I can't prove it scientifically. You just take this medicine. Have faith in me." When a patient fails to recover, the doctor says, "You must have made some mistake in taking the medicine. My medicine can't be wrong." Authorities will cancel the license of this doctor.
The followers of Shankaracharya can't prove their path scientifically. They blame the failed disciples for lacking faith.
A Shankaracharya follower says, "
So choose Science or Religion.
