> Vulcan-like lack of emotional investment

Using a weird pop culture cliché probably hinders you here ?

I would say what needs to be trained is instead emotional investment (this is probably redundant : no investment without at least former emotions ?) into trying to figure out the/a truth. For instance being bothered when some propositions seem to conflict each other.

And at least a bare minimum of investment into your beliefs is kind of required (though I guess that this is already what differentiates them from opinions ?), other way lies insanity.