‘When we teach zazen we often show a photo of an austere Zen monk sitting zazen with upright posture. We begin by saying, “This is a model for zazen. You should sit like this…” I usually show a photo of an infant sitting on the floor. Here is a photo of an eleven-month-old baby. I think we can learn a lot about zazen posture from this photo. According to Zen master Dogen, sitting upright with proper posture (shoshin tanza in Japanese) is the A to Z of zazen. Breath and mind will naturally be regulated by establishing proper zazen posture.
Please notice that this baby shows no sign of contrivance or pretentiousness. We do not see any strain or lack of naturalness. The baby does not seem to be thinking, “I should keep my back straight!” “I must not move!” “If I sit nicely, I will be praised.” He is effortlessly sitting comfortably. To borrow Dogen’s phrase, he sits “with no need for any expenditure of either physical or mental effort” (Shobogenzo Shoji). Nevertheless he is sitting firmly grounded on the floor so that his upper body stands up beautifully and freely, extending in the direction of gravity. He does this because his posture has spontaneously emerged from within as katadori (form), and not as katachi (shape) forcibly imposed from the outside.’ (from the Soto Zen Journal)