Please note I'm not a teacher nor a native speaker.
What strike me with the OP example is that although I think I understand the sentence in question yet I'm unable to give the answer to OP's question. And on top of that I can't fully agree with what already been said.
So I determined upon finding the answer. I decided that I weigh in even though I didn't find it.
Man was formerly thought to be a reasoning animal, basing his actions on the conclusions of natural logic....Momentous decisions are made, far-reaching actions are determined upon, primarily by the force of suggestion.
I understand that the second sentence could read :
Momentous decisions and far-reaching actions are based primarily on/upon the force of suggestion. [as contrary to 'basing it on the conclusions of natural logic']
But I wouldn't say that determined upon means based on/upon.I was searching for examples of usage in BNC to help me grasp the meanings of and the difference between determined upon and determined. I thought that I'd post it here. I hope it will be somehow helpful.
First some examples where I think is impossible to omit the preposition. [I'm not sure if it conveys the same meaning] :
- Presumably, if the House of Commons chose to determine upon the fate of a Bill by drawing lots or tossing a coin, it would be within its competence to do so.
- Having attained a First Class degree in History in 1935, he then determined upon a doctorate, which he completed in 1938
could the preposition be omitted ? :
- Once the pact made, action, and instantaneous action, was determined upon.
- In the course of inquiry objectives are set and a specific course of action is determined upon from a set of alternative courses of action.
- There must be some period at which the military and the diplomatic or political forces are brought together, and in my view, this ought to be before action is determined upon.
some sentences with upon + by.:
- Complaints were carried to Carthage, and war was determined upon bythe influence of Annibal in the Carthaginian senate
- All cases of amputation must either be first designated for operation by the surgeon in charge of the hospital, or be determined upon by a majority vote of a board of at least ...
[lot of the above examples are dating back to 1800's ]
some examples with determined by :
- Now if this only means what was before asserted, that our actions are determined by pleasure and pain, that simple and unambiguous mode of stating the proposition is preferable
- That is, we feel that our voluntary actions are determined by causes within us, and not outside us.
- According to this tradition, moral agents act autonomously when their actions are determined by their reason, rather than by irrational impulses, habits, or emotions.