Zen could be recognized as a school famous for valuing simplicity, practice, non-conditioned steps into direct experience, and non-conceptual insights.
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Minimal sex: It is neither visual image nor deity invocation but breath awareness that Zen puts forth. When malas are incorporated in Zen practice, instead of roof-vine and mantra, they may be viewed as aid in the shadowy counting of breath.
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Silent Presence: Instead of vocal mantras, Zen practitioners may count one bead per breath cycle silently. The repetition isn't about accumulation but about returning to the present moment, over and over, refining one's ability to remain fully aware.
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Not attached to form: In Zen, mala is often just other skills. Careful though, never to get attached. If a mala helps you concentrate, welcome it. If it ever turns out to be distracting, toss it aside. It encourages adaptation and flexibility.