Nichiren quotes Tientai on those who merely meditate without doctrinal study

"The seventh volume of On “Great Concentration and Insight” states: “‘Priests who concentrate on the written word’ refers to men who gain no inner insight or understanding through meditation, but concern themselves only with characteristics of the doctrine. ‘Zen masters who concentrate on practice’ refers to men who do not learn how to attain the truth and the corresponding wisdom, but fix their minds on the mere techniques of breath control. Theirs is the kind of [non-Buddhist] meditation that fundamentally still retains outflows. ‘Some Zen masters give all their attention to meditation alone’ means that, for the sake of discussion, T’ien-t’ai gives them a certain degree of recognition, but from a stricter viewpoint they lack both insight and understanding. The Zen men in the world today value only meditation [as the way to realize the truth] and have no familiarity with doctrinal teachings. In relying upon meditation alone, they interpret the sutras in their own way. They put together the eight errors and the eight winds, and talk about the Buddha as being sixteen feet in height. They lump together the five components and the three poisons, and call them the eight errors. They equate the six sense organs with the six transcendental powers, and the four elements with the four noble truths. To interpret the sutras in such an arbitrary manner is to be guilty of the greatest falsehood. Such nonsense is not even worth discussing.” - The Opening of the Eyes