I once tried reasoning with a large spider while my wife was standing on an adjacent chair, screaming "Kill it, Kill it!"
The spider seemed obstinate and would not listen to my well-reasoned arguments about better food supplies elsewhere and the likelyhood of being trod upon by Labrador retrievers while in my house.
So I killed it.
I actually put them in glass jars and take them outside. My reasoning is as follows:
I don't mind outdoor spiders.
I hate outdoor flies.