1. You can't change people's mind by force.
Only an ignorant person would not change their mind when presented with a logical and reasonable positions, littered with objective evidence, against their arguments. Once one encounters such a person, it's best to leave them to their ignorance, I've found.
They have to want to change.
They should be more prone to a proper education than winning an argument, but you're right, people need to accept that they don't know a lot of things and allow themselves to be taught. This would signify a "change", at least in their perspective.
2. People retreat to defensive, well fortified positions when threatened. It then becomes even harder to move them.
Only if one holds to the position that they have infallible information to counter you with. There is no defensive measure they should retreat to when one is simply trying to educate that person.
Their defensive measures are indicative of a weak position, it shows lack of confidence in their argument and usually takes any discussion into a childish debate.
It should be constantly challenged and questioned.
Yes, but by whom? Any crackpot off the street or well educated scientists that have presented an argument to the contrary using the scientific method of gathering evidence to support their hypothesis?
This is the key point to leaving an open door invitation to "challenge" science. It MUST be done properly for it to be affective.
I say bring 'em on. In the past, any theory that is valid has eventually won the day.
Faith cannot be contested against. Your point is moot if one is simply going to "challenge" science with their subjective beliefs.
What would be the point of allowing such an argument to be presented?
Not to mention the lowering of scientific standards that would have to take place for such metaphysical hypothesis to be given an open forum for scientific discussion.
- Oni
"I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your mouth."--Bill Hicks
"I never knew there was another option other than to question everything"--Noam Chomsky