Do you think it is better to approach zazen in a relaxed and calm way or in a more determined and energetic way? For example if before a zazen session I make a firm commitment not to remove my awareness from my breath no matter what is this OK or is this a mistaken thinking?


The samadhi of breathing is always samadhi. It does not start or stop, that is why it is called samadhi. There is no beginning or end to Zazen. The teaching of Zen in our lineage is: "Moving isĀ Zen, sitting is Zen, all movements are the source of natural settlednessĀ of your body." That has been the samadhi of zazen for the Buddha and all the patriarchs.