For smaller distances these theories are modified in a profound way.

These assumptions have been questioned and the theory has been modified since its original formulation.

When this happens, a theory must be modified or discarded altogether.

This theory has been greatly modified by the discovery of other conditions affecting wages, which it does not take into account.

When an increasing number of psychologists could not find what the theory required them to find, the theory was modified.

And theories are modified to fit facts.

Since Marx's time, the theory has been modified and expanded by thousands of Marxist thinkers.

Others argue that a moral theory that is so contrary to our deeply held moral convictions must either be rejected or modified.

The theory has been somewhat modified to fit subsequent experimental evidence, and some of the details are still debated, but its general thrust is widely accepted.

The theory has been criticised and modified over the course of time, as one of several competing theories.