It is easy to believe; doubting is more difficult. Experience and knowledge and thinking are necessary before we can doubt and question intelligently. Tell a child that Santa Claus comes down the chimney or a savage that thunder is the anger of the gods and the child and the savage will accept your statements until they acquire sufficient knowledge to cause them to demur. Millions in India passionately believe that the waters of the Ganges are holy, that snakes are deities in disguise, that it is as wrong to kill a cow as it is to kill a person - and, as for eating roast beef…that is no more to be thought of than cannibalism. They accept these absurdities, not because they have been proved, but because the suggestion has been deeply imbedded in their minds, and they have not the intelligence, the knowledge, the experience, necessary to question them. We smile…the poor benighted creatures! Yet you and I, if we examine the facts closely, will discover that the majority of our opinions, our most cherished beliefs, our creeds, the principles of conduct on which many of us base our very lives, are the result of suggestion, not reasoning… Prejudiced, biased, and reiterated assertions, not logic, have formulated our beliefs. - Dale Carnegie
I like Dale Carnegie in general and think his intentions are good, but disagree with this quote. A different user posted this link a couple weeks ago, I find it relevant: http://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1004&context=eng_faculty_pubs
Naive believing is easy, but not sophisticated believing. This is similar to how naive doubt regularly fails.
Quotes are a unique enough medium of expression that I'm interested in viewing quotes that people have found collectable, emotionally impactful, useful, memorable, or otherwise noteworthy - perhaps others are similarly interested. To clarify, these need not be even remotely related to rationality. I'm hijacking the mandates traditionally used for the Rationality Quotes thread, with a few modifications:
Please post any meta discussion in the top-level comment named "Meta".