Zazen

Zazen is not observation of thoughts because observation and thought are incompatible. Thought about x involves attention to x, not to the thought about x.

Zazen is neither deliberate thought nor uninterrupted natural thought but natural thought interrupted by a repeated return of attention to the present moment.

Thus:

deliberate thought is not applied to problems that it cannot solve;

natural thought is allowed neither to become deliberate thought nor to continue uninterrupted.

This at least provides a third perspective. Many problems are caused either by constant natural thought or by unhelpful deliberate thought.