The error lies in thinking they're 'real' systems to be taken for granted and blindly reasoned forward from, instead of sometimes-helpful academic categorizations.
You can always factor things into groups. e.g. 'Thoughts about now vs thoughts about the future'. Extending that to say there are therefore two modes of thinking and that the brain must handle your two groups differently, at some fundamental or physiological level, and there are only these two modes and all things are either one or the other ... is perhaps quite misguided without more support.
I don't think we have conclusive evidence, but everything that I see from myself it makes sense to categorize like that. It is either a quick intuitive guess or feel or alternatively I have to hash it out. It just fits perfectly to me.
I do think they are systems in a sense that one is optimsed to be a quick system and the other one requires time, but can solve tougher problems, create something new.
It seems fundamental to me that it is how things would get organized.
You can always factor things into groups. e.g. 'Thoughts about now vs thoughts about the future'. Extending that to say there are therefore two modes of thinking and that the brain must handle your two groups differently, at some fundamental or physiological level, and there are only these two modes and all things are either one or the other ... is perhaps quite misguided without more support.
"It's only a model"