I think Zen is a philosophy and a way of life. If you go to the book store to find Zen books in English, you can only find them in the philosophy section. The Westerners have long regarded Zen as a philosophy.
Zen was introduced into China from India. Unlike other schools of Buddhism, Zen has no scriptures, and does not even rely on text as its communication medium. It uses the heart to pass on the heart. Words cannot fully express Zen. Zen can only be comprehended in the heart. For a period of time, Zen was very prosperous in China. There were many famous Zen masters, as well as many dignitaries and scholars actively participating in Zen practice. Although Zen is a faction of Buddhism, it advocates individualism and conflicts with Confucianism. Zen posed a certain threat to its rulers and was suppressed. There were many Japanese Zen masters who traveled to China to study Zen, and many Chinese Zen masters traveled to Japan to teach Zen. Zen was very prosperous in Japan. Zen in English is properly originated from Japan. It is possible that most of the western works on Zen were originated from Japan.
There is no fixed way for Zen practice. You don't even need to meditate, to study the scriptures, to worship the Buddha. You can even curse the Buddha if you think it is the right way for you. Zen enlightenment is epiphany. It's not gradual. It is sudden enlightenment. Some Zen practitioners could not enlighten for decades, but they still could enlighten in an instant. The ancient Zen masters used shouting and stick banging without warning to help the practitioners to achieve enlightenment. Shouting and stick banging without warning may help the practitioners to achieve epiphany. After achieving enlightenment, the state of enlightenment cannot be revealed in words. If you can say the state of enlightenment, then you may not have enlightened. Although Zen cannot be said and there are no scriptures, but there are some Zen cases and stories to help people to practice or to comprehend.
The purpose of Zen practice is to improve one's quality of life, to increase one's self-confidence, and to become more forgiving, decisive and happy. If you can apply Zen practice in your daily life, it would be pragmatic. Meditating is not something everyone can do. It's not easy to be “not thinking”. When many people sit and do nothing, they will think wildly. Even if they can stay in the ‘not thinking’ state and achieve ‘absolute solitude’, how is it different from the deep sleeping state? If the results of Zen practice cannot be applied to daily life, then I don't understand the purpose of Zen practice. What's the benefit of becoming ‘absolute solitude’?