Question

What does the phrase, "Lost The Use Of Reason" mean?

Answer 1

If you are using reason in a philosophical sense, its meaning is "the capacity for logical and rational thinking".
When someone loses their use of reason (generally out of rage), they may begin to do things they generally wouldn't (like actions that go against their morals.
For example, if a man becomes so enraged at another, he may lose his use of reason and begin to act irrationally by yelling at, harming, or even killing the other man.
Does that make sense?