>>>>In general: An ideology you use as the point of view.
>>The filter you put all your input through.
>>
>>Perhaps prejudice?
>
>That's exactly our problem, John.
>We would-be-rational-free-thinkers have done a good job, going back centuries, of debunking myths and exposing prejudices, but we haven't offered much as a replacement.
>Reason?
>Sure, Reason is marvellous, but picture yourself as an infantry platoon leader telling the members of his platoon that they'll face death so that Reason can prevail!
>If you watched Obama's oval office speech after the San Bernardino killings, you'll know what I mean.
>Intellectually, it was sound.
>
>But it had all the leadership qualities of someone reading the Hamilton, NJ telephone directory.
>It was probably the worst speech I've ever heard from a US president.
>Compare what he said to "Ask not what your country can do for you... " or "Mr Gorbachev.. tear down that wall.."
>The missing ingredient was weltanschhauung.

You certainly have mentioned a valid point. But the irrational part of Weltanschaung (no double "h") can also have negative effects of evolution in action on its subscribers. My father took active steps to be captured in WWII on the west front and spent some time as a POW in the states and not in the USSR and he did not enter the military led by Nazi speeches but as one way where he did not have any good options left. He was able to sire me ;-)

A lot of the guys having something akin to jihadist mentality were culled from the gene pool in germany in the first half of last century. I just hope there are enough rational beings around if/when jihadist mentality comes visiting here to stop them from overrunning. (I do not consider the open end invitation of Merkel rational, but have no access to the base info she decides upon)