Wittgenstein says in the Tractatus:
6.3211 Men had indeed an idea that there must be a 'law of least action', before they knew exactly how it ran. (Here, as always, what is certain a priori proves to be something purely logical).
What evidence does he have for this?
For example, Hero of Alexandria showed that the motion of light followed the path of least distance.
Was there any speculation at the time or post this, or before, that this law could be generalised?
Could one say that Leibniz had a least principle? The 'reflection' of least is best. And he did say that God created the 'best of all possible worlds'.