Overall, there are two kinds of emotional motivations: pleasant (will be referred to as "positive") and painful (will be referred to as "negative"). Either a man acts to gain pleasure, or to avoid pain. These are essentially the two forms of emotional motivation man experiences.
For example: we can be motivated to build a house out of a sense of pleasure. We can run away from a snake because of fear. We can give money to a beggar to avoid guilt, or we can buy a gift to a friend because of pleasure. We can study for a test because we are afraid to fail it, or we can read a book because we enjoy training ourselves in rational thinking.
These examples illustrate an additional implicit understanding - that emotions are motivational force for action.
The positive and the negative categories of emotional motivation are not meant to play an equal role in man's life.
Negative motivation is meant to help us avoid damage - to deal with disaster and prevent it. To that extent, it is an excellent servant, and useful for our lives.
Positive motivation is meant to motivate us for the rest of our actions in life, in the pursuit of values. Values such as food, house, entertainment, friends etc'.
Take this opportunity to stop and think for a moment: Is the pursuit of such values in your life a result of positive motivation or negative one? Are you moved in your work by a sense of pleasure, or by a sense of duty? Do you do what you think is moral out of duty, or out of pleasure?
Motivation in pursuit of values should be from positive emotions, not from negative ones.
Assuming that the pursuit of values is the norm of every day life (what we do most of the time), and disasters are exceptional and rare, motivation from negative emotions should only be present in exceptional cases of correcting a mistake, or when you try to deal with some disaster - but not on the form of daily basis.
It is important to keep in mind that negative emotions do have a significant role, too. Suppose you did something wrong, like, say, acting unjustly to a friend. You would feel guilt, and this will motivate you to correct the injustice. Acting on negative motivation in this case is proper.
How do you decide what is proper? Reason is always the final arbiter. But listening to your emotions is an important first step to suggest an action.
So let's look at an example of improper negative motivation: forcing oneself to do well at school, because of viewing it as an instance of the virtue of productivity. Doing well at school in most cases is NOT a matter of productivity at all (because school is not fully rational), studying becomes a constant action despite boredom and pain. "If you want to be good - you must try to be a good student. To be a good student - you must learn to endure pain".
The result is going through years of putting an effort into school because of a desire to avoid a sense of guilt and failure.
But the process of acquiring knowledge required for your career is pursuit of a value - not an attempt to avoid disaster or correct a mistake. Is it right that instead of pleasure, all one would feel is the pain of duty and self-repression? No. Such a clash is a call to look for a mistake in one's thinking (as I learned the hard way), not a call to continue things as the day before.
This example demonstrates how rationalism leads to living one's life under negative motivation - out of a sense of duty to obey moral principles, not out of sense of acting selfishly to achieve one's pleasure. (The rationalist idea, in this case is to decide arbitrarily that success in school has to be, regardless of its actual nature, the virtue of productivity).
Now what would be the long-term consequence of motivation from negative emotions in pursuits of values? Over time, it destroys everything it touches.
In schools, kids are taught that they are good if they learn despite being bored. Over time the result is that they come to hate learning. Not just learning at school, but the act of putting mental effort into anything.
As an adult, you may start with a job you dislike, training yourself over time not to notice your boredom. After enough time, you lose motivation to do any kind of work at all, even one you could have enjoyed before. How did this happen? you trained yourself to make your emotions irrelevant to your actions. You trained your subconscious to associate "work" with suffering and self-compulsion.
If you view morality as a duty to hold yourself to - you will continually repress personal desires in order to be "in-line" with those principles. At the end of this road, you either lose sight of what "you" is, or you throw morality completely and attempt to live without principles at all.
The pursuit of moral values, or virtues, or becoming the hero you have in your mind - should be from positive emotions.
If it is not, that is the time to stop and think - make sure you really understand the principles you attempt to live by. Make sure you can see how those principles are good for you.
There is only so much time that negative motivation can carry a man.
This motivation is meant as a temporary assistant - not as fuel for every-day actions throughout life. This motivation is "crash and burn", its end result is always bad if used to pursue values.
After 4 years of stress and repression I had in the technological institute I studied in, I know.
To the extent that a society is irrational (like bad schooling system), some conflicts are bound to cross your way.
In a dictatorship, one's actions are motivated by fear as the only possible way to function.
But - Taking whatever existing conditions under account, try to pursue your values by the desire to gain pleasure. It is selfish. It is good. It is what makes life worth living.