Our past cannot be changed, and to be preoccupied with it is inefficient in time and effort. Likewise, by fretting over the future, we only exhaust ourselves, making us less able to effectively respond when the future is actually upon us. By worrying about a mishap that may or may not take place, we’re forced to undergo the event twice—once when imagining it and once again if and when we actually experience it.

Basically, if the mind stays in the present, it’s impossible to worry. Upon careful consideration, it becomes clear that human beings are capable of worrying only about an event that has already transpired or one that may take place in the future (although the occurrence might have just happened or may be about to happen in the next instant). The present moment contains no time or space for worry.

By keeping the mind in the present, unless you deliberately want to contemplate the past or future, it’s possible to firmly face life without fear. Then, no thoughts of past failures or future problems will exist in the mind, and a truly positive mental state will result—fudoshin, the “immovable mind.

Using the combined, integrated force of the mind and body is more efficient than using one without the other. Since the body can only exist in the present, that’s where the mind should be too (unless we deliberately choose to contemplate the past or future). At the same time, the body needs to be healthy and in optimum operating condition so that it can respond effectively to the mind’s directives.