1.) Scientists are ordinary because they, like most people, are reluctant to change unless given evidence for why they should.
2.) No, they are not. He says "he will accept a new theory only if it stands the trial of many experimental tests." This means that people will only change their thinking if they're given plenty of reliable and verifiable evidence.
3.) Yes, theories can gain acceptance. But they have to be verified. Experiments have to be conducted. A theory isn't just accepted right away.
4.) Science would no longer be about facts or using reasoning. It would become a field of speculation and contrived ideas that are constantly being disproven. People would lose faith in scientists and the entire field would be discredited.
