Sentence:  But the other, because he's been immersed in arguments, gives the appearance of harbouring considerable <WSD>anxiety</WSD> and suspicion that he's ignorant of those matters he presents himself to others as an expert on. 
Meaning of the word marked with <WSD> tags:  An unpleasant state of mental uneasiness, nervousness, apprehension and obsession or concern about some uncertain event.