2/ Then, whether the movement of air is from your breathing or a brush from the fan is not a form or feeling or perception or mental formation or aspect consciousness that may be discerned.

1/ "The most fundamental expression" because, when we sit zazen and just keep proper posture and follow our breathing, making no effort - not to accomplish, or plan, or achieve, or advance, or become *anything whatsoever* - the emptiness of the five skandhas may become apparent.