Cohen was born in
Maišiagala, near
Vilna (in modern
Lithuania), the scion of a distinguished rabbinic family. In his youth he studied at the
Raduń Yeshiva under Rabbi
Yisrael Meir Kagan, at the
Volozhin yeshiva, and at the
yeshiva in
Slabodka. Even at that time, his restless and inquiring mind led him to extend his studies beyond the traditional subjects taught in the yeshivot. Thus he turned to Rabbi
Samson Raphael Hirsch and the early writings of Rabbi
Abraham Isaac Kook. He also studied
Russian to prepare himself for entrance to the university. During the
Russian Revolution of 1905 he was twice arrested but was not detained. His spiritual unrest and the desire to widen his intellectual horizon led him to enroll in the Academy for Jewish Studies established by Baron
David Guenzburg, where one of his close fellow students was
Zalman Shazar, later president of Israel. From there he proceeded to Germany to study at the
University of Freiburg. At the outbreak of
World War I he was interned as an enemy alien, but was released and made his way to Basel, Switzerland, where he became involved in the Jewish Community while continuing studying Torah and also studying philosophy, classical literature, and Roman law at the University of Basel. He was for a time chairman of the Jewish Students' Society there and delivered lectures on Jewish philosophy. It was then that he took upon himself a lifelong
Nazirite vow, which involves complete abstention from cutting one's hair and partaking of any products of the vine. However, his personal asceticism went further: he became vegetarian, eschewing not only meat but also any garment made of leather, and practised self-imposed silence vows (referred to in Hebrew as "Speech Fasts") on a regular basis. A weekly silence every Shabbat; a monthly silence every Rosh Hodesh Eve (
Yom Kippur Katan), and the highlight - an annual silence period of 41 days from Erev Rosh Hodesh Elul to the end of Yom Kippur. In addition, despite being proficient in [9] languages, he refused to speak anything but the Holy Language - Hebrew. Additionally, from the capture of the Old City of Jerusalem by the Jordanians in
1947–1949 Palestine war until the capture by the IDF in the Six-Day War (1967), he vowed not to leave his home. Finally, since Israel's independence (1948), he vowed not to leave the Holy City of Jerusalem and, in fact, left Jerusalem only on 3 occasions after that (24 years until his passing), with each such departure being formally approved by a special Beith Din (a Rabbinical Court) granting him temporary permission to depart from his undertaking. However, he was not a recluse and was extremely warm, welcoming and respectful towards any person who came to see him, regardless of this person's status, age, or in many cases, eccentricities. Rabbi Cohen was fully aware of the day-to-day occurrences in Israel and did not hesitate to publicly express his views on important topical issues. ==Meeting Rabbi Abraham Isaac Kook==