This absolute knowledge is like the intrinsic fullness of the moon, which is unaffected by its apparent waxing and waning.

~Jnaneshwar

Knowledge that is acquired is not like this. Those who have it worry if audiences like it or not. It's a bait for popularity. Disputational knowing wants customers. It has no soul... The only real customer is God. Chew quietly your sweet sugarcane God-Love, and stay playfully childish.

~Rumi

My words are very easy to understand

And very easy to practice.

Still, no one in the world

Can understand or practice them.

My words have an origin.

My deeds have a sovereign.

Truly, because people do not understand this,

They do not understand me.

That so few understand me is why I am treasured.

Therefore, the sage wears coarse clothes, concealing jade.

~Lao Tzu

Perhaps, the article showcases a confusion between the knowledge of the world, deemed philosophy, and the knowledge of the absolute, also called philosophy. Hence, there is philosophy as interpretation and argument on the one hand, and philosophy as revelation on the other. This is seen in the philosophers listed in the article.