75. “There are essentially two forces that motivate people: self-interest and fear.”
“有两种驱使人们的基本力量：自私和恐惧。”
Self-interest an fear are two important forces that motivate people. But I can not totally agree with the author's assertion that the above-mentioned two forces are the only forces that motivate people.
1.       Fear and other survival instinctions can motivate people to do some basic and essential activities such as eating, drinking, living with others, and so on so forth.
2.       Self interest is the initiative for people to do some further explortions. That is the motivation for us to study, to hold a certain type of expertise or technology, etc.
3.       However, the author ignore the other aspect of mankind other than the selfish nature--altruism.
 
1.      不能否认的是，人们做很多行为都出自这两种天性。a, 人们努力工作，为了赚足够的钱养活自己，support the family，人们接受education and training to make sure that he or she can grasp the up to date knowledge and skills for the purpose to avoid being supplanted by others. 因为恐惧。b, 人们遵守社会规范，有时也是为了赢得reputation。
2.      但是，如果说人的一切行为都root in these only two factors, 这就过于one-sided的说法。忽略了other aspects of the natural humanity。比如人性中的很多美德，都表现了人们克服了selfishness and fear取得的成就。a, 科学家为了address the problem of starvation, 花一生的精力去研究the better rice breed. b, anonymous charitarian donate huge amount of money to the school and hospital…people can hardly be persuaded to believe that the anonymous charitarian doing so are only motivated by the intention of gaining reputation.
3.       过于片面。

Optional words:
Motivate/ provoke/ stimulate/ excite/ prompt/ arouse/ encourage/ incite/ inspire
Fear/dread/ alarm/ terror/ scare
Thesis sentence: While self-interest and fear are two important forces that motivate people, they are not the only forces that motivate people. the speaker oversimplifies human nature, ignoring the important motivating force of altruism.
View1: On the one hand, I agree that most of our actions result in large part from self-
interest and from our survival instincts, such as fear.
Evidence: educational and vocational lives are motivated by interest in ensuring our livelihood, safety, health and so on.
View2: On the other hand, the assertion that all of our actions are essentially motivated by self-interest and fear is based on the belief that human beings are essentially selfish, or egoistic. Thus, overemphasize one aspect of human nature. Humans are also altruistic—that is, we act to benefit others, even though doing so may not in be in our own interest.
Evidence:
 
The speaker claims that people are motivated only by fear and self-interest. This claim relies on the belief that human beings are essentially selfish, or egoistic. In my view, the speaker oversimplifies human nature, ignoring the important motivating force of altruism.
On the one hand, I agree that most of our actions result in large part from self-interest and from our survival instincts, such as fear. For example, our educational and vocational lives are to a great extent motivated by our interest in ensuring our own livelihood, safety, health, and so on. We might perpetuate bad personal relationships because we are insecure—or afraid—of what will happen to us if we change course. Even providing for our own children may to some extent be motivated by selfishness—satisfying a need for fulfillment or easing our fear that we will be alone in our old age.
On the other hand, to assert that all of our actions are essentially motivated by self-interest and fear is to overemphasize one aspect of human nature. Humans are also altruistic—that is, we act to benefit others, even though doing so may not be in our own interest. The speaker might claim that altruistic acts are just egoistic ones in disguise—done to avoid unpleasant feelings of guilt, to give oneself pleasure, or to obligate another person. However, this counter argument suffers from three critical problems. First, some examples of altruism are difficult to describe in terms of self-interest alone. Consider the soldier who falls on a grenade to save his companions. It would be nonsensical to assert that this soldier is acting selfishly when he knows his action will certainly result in his own immediate death. Second, the argument offends (违反) our intuition that human motivation is far more complex. Third, it relies on a poor assumption; just because we feel good about helping others, it does not follow that the only reason we help is in order to feel good.
In sum, the speaker oversimplifies human nature. All human motivation cannot be reduced to fear and self-interest. We can also be motivated by altruism, and the pleasure we might take in helping others is not necessarily an indication that our actions are selfish.