Eckhart Tolle opens The Power of Now with his foundational spiritual premise: the present moment represents the only genuine reality anyone ever actually experiences, while the past and future exist only as mental constructs — memory and anticipation — that, when given excessive attention, actually obscure this present-moment reality and produce unnecessary psychological suffering.

Tolle's foundational argument:

• He argues that psychological suffering — anxiety, regret, dissatisfaction — stems predominantly from excessive mental attention to the past or future, rather than from the genuine present moment itself, which Tolle argues is rarely, in itself, genuinely unbearable when experienced directly without this mental time-travel
• Tolle distinguishes between the practical use of memory and planning — genuinely useful cognitive tools when applied to actual present tasks — and excessive, compulsive mental time-travel that pulls attention away from direct present-moment experience without corresponding practical benefit
• This foundational premise, drawing on various spiritual and meditative traditions while presented in Tolle's own distinctive, accessible language, sets up the book's overall project: helping readers recognize and reduce this compulsive mental time-travel in favor of greater present-moment awareness

This foundational framing establishes the book's overall approach: examining the specific mental patterns — Tolle's concept of the "ego" and "pain-body" — that pull attention away from present-moment awareness, and providing practices for returning attention to this present-moment reality.