This makes absolutely no sense, "The gentlest thing in the world is an open mind", just the absolute nature of this statement means the author does not have an open mind. "Since it doesn't believe what it thinks, it's flexible, porous without opposition," if you don't believe what you think, how could you begin to present this philosophy? How can you write an article or present an opinion without thought and without presenting those thoughts in the form of a belief? This entire article is written from one persons view and perspective on the world, those views and perspectives are generated from our thoughts and our beliefs and our experiences, that is why this article is not open minded at all, it's a very definitive view on why people should have an open mind.
Hence the problem with this persons philosophy in general and even outside this article, how can you teach people to question beliefs and thoughts without running into a circular problem? How can you ask people to question their thoughts and beliefs and attach no value to them without questioning your thoughts and beliefs in asking them to question their thoughts and beliefs? Why do your thoughts and beliefs have value? And theirs don't? If your philosophy is meant to be universally applied than you have a huge fallacy in your philosophy and a circular problem.
And I think you should apply your own thoughts and beliefs on the matter and question the entire philosophy, ask yourself, "is it true"?