Because there were contributing factors, things that speak to states of mind.
There were a number of contributing factors to take into account.
He also speculated that his personal problems may have been contributing factors.
There were a number of contributing factors which helped to create the consumer revolution.
Education background, experience, and level of practice all are contributing factors to which salary is established.
Ask him about the 90's boom and he cites contributing factors beyond any president's control.
These differences may have been contributing factors to the eastern empire's survival.
It is possible, however, that those were contributing factors to my descent into madness.
In addition, all patients should be fully evaluated for contributing psychological factors.
There were a number of contributing factors to this.