Why do I so strongly want to believe that forces cause accelerations?
A possibility: Many people are constantly exposed to
examples where they *calculate* the acceleration based
on prior knowledge of the force, not vice versa.
In such a case, it is correct to say we _know_ the
mass*acceleration because we _know_ the force.
But this does not prove that F causes ma, for multiple
reasons:
1) Examples, even innumerable examples, do not prove
the general case, especially when there are counterexamples.
For instance, if I tell you the mass, radius, and
rotation-rate of a centrifuge, you can calculate the
acceleration and thence calculate the force.
2) As a point of fundamental logic, the cause of our
*knowledge* of ma is not the cause of ma itself.
3) Cause should precede effect. The force F does
not precede the acceleration a=F/m ... they must
both happen at the same time.