The policeman decided to act on the basis of his informants phone call.
I am but the magistrate of the republic. I merely act upon the imagination of the nation.
It has often been said of the Japanese that they are slow in forming a decision but very quick to act upon it.
These " weathering " agents not only act upon stones of buildings, but upon rocks of all kinds, reducing them sooner or later into a more or less fine powder.
Extension and thought, the essences of corporeal and spiritual natures, are absolutely distinct, and cannot act upon one another.