根据下面资料，回答题
Laziness is a sin. Everyone knows that. We have probably all had lectures pointing out that laziness is immoral, that it is wasteful, and that lazy people will never amount to anything in life.
But laziness can be more harmful than that, and it is often caused by more complex reasons than the simple wish to avoid work. Some people who appear to be lazy are suffering from much more serious problems. They may be so distrustful of their fellow workers that they are unable to join in any group task for fear of being laughed at or fear of having their ideas stolen. These people who seem lazy may be deadened by a fear of failure that prevents fruitful work. Or other sorts of fantasies may prevent work: some people are so busy planning, sometimes planning great deals of fantastic achievement, that they are unable to deal with whatever "lesser" work is on hand. Still other people are not avoiding work, strictly speaking; they are nearly procrastinating—rescheduling their day.
Laziness can actually be helpful. Like procrastinators, some people look lazy when they are really thinking, planning, researching. We should all remember that some great scientific discover-ies occurred by chance. Newton wasn' t working in the orchard when the apple hit him and he devised the theory of gravity. Taking a rest can be particularly helpful to the athlete who is trying too hard or the doctor who' s simply working himself overtime too many evenings at the clinic.
So be careful when you're tempted to call someone lazy. That person may be thinking, rest-ing or planning his or her next book.
 The main idea of this passage is that__________.