Is Schopenhauer's "the Will" equivalent to "the Mystic Law"?
I know next to nothing about Schopenhauer but the Nichiren sect of Japanese Buddhism focus on the sutra popularly known as Lotus Sutra - the 妙法蓮華経 Myōhō Renge Kyō which is in turn from Chinese 妙法蓮華經; pinyin: Miàofǎ Liánhuá jīng, which is ultimately from Sanskrit Saddharmapuṇḍarīka Sūtra literally Sutra on the White Lotus of the Sublime Dharma. So "Mystic Law" is just a re-translation of "Sublime Dharma". Now I am no expert on the text but I believe the 'Sublime Dharma' refers to All of Existence and Phenomena. So this concept is only tangentially related to the Will or Collective Consciousness described by Schopenhauer.