Sources of Illogical Thinking

1. Skepticism is a mistake in reasoning when it is not selectively employed. Selectively employed skepticism means that we should reserve judgement until we have sufficient information at hand to judge responsibly, However, skepticism becomes a mistake in reasoning when we have it as a permanent attitude because this subverts the reasoning process before it even gets started, transforming it into a process of misreasoning. An agnostic is someone who maintains that he lacks enough knowledge regarding a particular issue to be able to make a definite judgement about it. Unlike a skeptic, an agnostic neither denies the existence of truth nor its attainability. An example of agnosticism as a mistake in reasoning is evasive agnosticism, using ignorance as an excuse rather than a reason, and such ignorance is the result of ignorance or laziness. Narrow-mindedness is a mistake in reasoning when one refuses to consider certain alternatives only because they do not meet his prejudiced assumptions about what is and what is not worth pursuing. Unlike agnostics, narrow-minded people do not use ignorance as an excuse but instead impose limitations on something. Unlike skeptics, narrow-minded people do not make premature judgements but instead solely on their prejudices. 
2. Example of Evasive Agnosticism: Suppose my math teacher asks me to research Unit Circle Trigonometry so I can give a mini-presentation to the class. If I do not bother to research Unit Circle Trigonometry and say that "I don't know" after I haven't bothered to research, I succumb to evasive agnosticism. In this case, I am using ignorance as an excuse, and my ignorance is the result of my laziness to complete my assignment.