Sakyamuni Buddha tells a large gathering:
"This is why we practise full lotus sitting."
Then the Thus-Come, the World-Honored One, taught his disciples that they should, like this, sit.
Among those who stray from the way some seek enlightenment by constantly remaining on tiptoes, some seek enlightenment by constantly standing up, and some seek enlightenment by constantly carrying their legs on their shoulders. Mad and stubborn mind like this is sunk in the sea of falsity, and the physical form is not quiet.
Therefore the Buddha taught his disciples full lotus sitting -- sitting that rights hearts and minds. How so? Because, when we allow the body to be upright, the heart tends to mend.
When the body itself rights sitting, then the heart is not faint and, with open heart and true mind, we tether our attention to what exists before us.
If the mind races or becomes distracted, if the body leans or becomes agitated, [sitting] inhibits this and brings us back. When we want to experience samadhi and want to enter samadhi, and yet all kinds of thought-chasing and and all kinds of dissipation is going on, [sitting] totally puts a stop to all this.
Training and learning like this, we experience and enter the samadhi that is king of samadhis.
"The body itself rights sitting" may better reflect the core principle of FM Alexander, based on his observation in action of the 2nd law of thermodynamics, that the right thing does itself. At the same time, it may be as close as I can get to the literal translation of the original four characters.