Recently, a person said if people gave him money, he would make them all rich. Gullible people invested with this man, and they lost all they had. Another person claimed he had this strange ointment which would make bald people grow hair. His scam was unveiled when someone unknowingly bumped him and his hat fell off. Guess what? He was bald himself. Another said he had found the secret to long life. Now people are waiting to see if it works on him!
Doubt , especially honest doubt is good. It keeps us from being gullible. Skepticism, on the other hand, is not good. I'm going to define skepticism as "dishonest doubt. "
Some skeptics in early philosophy classes doubted that they themselves existed. They went about asking questions like, "Do I exist?" By the way, if any one asks you, "Do I exist?" Ask him if he is serious. If he says, "Yes!" Ask him who is asking the question. If he says, "I am." He has just confirmed his existence.
All unusual claims need to be doubted, but in honest doubt. The issue is not doubt per se. The issue is on what terms you will accept something, some statement, some event as true. That's were the difference is between doubt and skepticism.
Those who aren't willing to accept anything as true are prisoners to skepticism—dishonest doubt. They take a hard approach on all aspects of life.