what role does critical thinking play in humanities
The more you use a language (through reading or learning new words somehow) the more your neurons your brain is making. With more paths in your brain the more information you can store. Thus language does play a role in critical thinking. Not much - the actual process of critical thinking, of distinguishing sound reasoning from unsound, is pre-verbal. Language only comes into play in importing the conditions to be critically thought about and exporting the results arrived at. This is my own on-the-fly opinion, not something I've proven or seen proven.