Question: You said that because we are not like rocks it is only
natural that thoughts come to our minds when we sit zazen, but it seems that when I sit zazen an unusual amount of delusions
and fantasies arises. 'What should I do?
Reply: It's not that an excessive amount of delusion and fantasy
arises because we do zazen. Usually, we live surrounded by even
more delusion and fantasy, but we are so steeped in it that we
become numb to these delusions and fantasies. Therefore, we
exist without even knowing that delusions and fantasies are
arising. Conversely, because we become still during zazen, we
clearly see in relief our own condition of being filled with delusion
and fantasy. It only seems that we have more delusion and fantasy
than usual.
However, as I have repeatedly mentioned, zazen is never an
attempt to extinguish these delusions and fantasies. Because even
the arisal of delusion and fantasy is our life force, there is no
reason to think that we should extinguish it. And yet, needless
to say, to be carried away by the state of delusion and fantasy is
to injure life itself. Because during zazen we let go of these
thoughts, delusion and fantasy become something which exists
and yet fades away. Therefore, zazen transcends ignorance and
satori and goes beyond the sages and the ordinary man.
from Approach to Zen by Kosho Uchiyama Roshi
https://terebess.hu/zen/mesterek/Approach-to-Zen.pdf
