What is Chan?
Chan exists universally and eternally. There is no need for any teacher to transmit it; what is transmitted is just the method by which one can personally experience Chan. In China, the Chan school developed from Indian Dhyana Buddhism, which taught methods of meditative concentration aimed at the attainment of an absorbed, concentrated state of mind. This school later spread to other countries from China, and is called Zen in Japan, Son in Korea, and Thien in Vietnam.
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Chan starts with gaining thorough knowledge of one's own self. Through letting go of all attachments and giving rise to wisdom, our mind can regain its luminosity. We call this knowledge of the notion of self "enlightenment" or "seeing one's self-nature." This is the beginning of helping yourself to thoroughly solve real problems. In the end, you will discover that you as an individual, together with the whole of existence, are but one indivisible totality.
Chan encompasses four key elements: faith, understanding, practice, and realization. Faith belongs to the realm of religion, understanding is philosophical, practice is belief put into action, and realization is enlightenment. Without faith, we cannot understand; without understanding, we cannot practice; and without practice, we cannot realize enlightenment. Together, these four concepts create the doorway we enter to attain wisdom.