Eihei Dogen, also known as Dogen Zenji, was a Japanese Buddhist monk and philosopher who founded the Soto Zen school of Buddhism in Japan. His teachings have had a profound impact on modern Zen practice, shaping the way it is understood and practiced in the present day.

One of the key teachings of Dogen that has had a lasting impact is the concept of zazen, or seated meditation. Dogen emphasized the importance of zazen as a means of attaining enlightenment and understanding the true nature of reality. He believed that through sitting in stillness and silence, one could experience the true nature of existence and connect with the ultimate truth.

Dogen's teachings also emphasized the idea of non-duality, or the non-separation of self and the world. He rejected the idea of a separate self and emphasized the interconnectedness of all beings and phenomena. This concept is still a fundamental aspect of modern Zen practice, as it encourages practitioners to let go of the ego and embrace the oneness of all things.

Another significant aspect of Dogen's teachings is the emphasis on the present moment. He believed that the only way to truly experience life was to be fully present in each moment, without being distracted by thoughts of the past or future. This idea is still central to modern Zen practice, as it encourages individuals to let go of attachments and live in the present moment.

Dogen also placed great importance on the role of the teacher in Zen practice. He believed that a qualified teacher was essential for guiding students on the path to enlightenment. This emphasis on the teacher-student relationship is still present in modern Zen practice, as students seek guidance and instruction from experienced teachers.

Additionally, Dogen's teachings on the concept of emptiness, or the idea that all things are impermanent and without inherent existence, have had a significant impact on modern Zen practice. This understanding of emptiness encourages practitioners to let go of attachments and expectations, and to embrace the impermanence of life.

In conclusion, Eihei Dogen's teachings have greatly influenced modern Zen practice, shaping its core principles and practices. His emphasis on zazen, non-duality, the present moment, the teacher-student relationship, and emptiness continue to guide and inspire Zen practitioners around the world.