Shaddha means faith. A kind of deep sense of what this person says and what these texts say is true, but I don't get it yet, but it's true. Without this, no investigation is possible. You can't sign up for a course in Columbia University if you don't have Shaddha on the syllabus... If you say it's all wrong, why would you pay thousands of dollars to listen to something that's all wrong? So that kind of Shaddha is very necessary.