Intellectual advancement depends upon the ability to take what has been learned by others and build on it. Each human being does not have to rediscover everything personally. It is, therefore, critically important that what you learn from others and use as your foundation be correct, or your own work will be flawed.
Often, you determine whether particular ideas are authoritative based on your appraisal of the person who said them, or the authority of the expert. It is extremely important to determine why you should believe that the author has the expertise necessary to create authoritative ideas.
However, you have to remember, experts can be wrong. Be highly critical all the time and do not accept ideas that do not seem logical or are insufficiently supported with evidence.
