In today's world, insurance plays a vital role in the economic and social welfare of the entire population. The wish to guard against dangers to life and property is basic to human nature. By using various kinds of insurance, society has been able to reduce the effects of such hazards. Nowhere is insurance more important than in the management of a business. In many instances, losses in a small firm can mean the difference between growth and failure, vitality and stagnation (停滞).Very few small businesses have even a portion of the financial resources available to larger enterprises. Frequently, they must operate on a very slight margin if they hope to stay in business. And thus, they are particularly sensitive to unexpected losses. Without enough insurance, what happens to such a firm when the owner dies or is suddenly disabled? When a fire breaks out and destroys the firm's building or stock? When an employee is found to have stolen company funds? When a customer is awarded a liability judgment for an accident? Too often, the business isforced to the wall, its future operations drasticallycurbed; sometimes, it is damaged beyond repair, its ability to continue completely crushed. Almost always, a small businessman would find it impossible to handle the full burden of his potential risk. The amount of money he would have to set aside to cover possible losses would leave him nothing, or almost nothing, to run his business with. If loss were to occur which he could repair by using his reserve fund, what assurance would he have that another loss—the same kind or different—might not occur next week, next month? But then he would have no reserve fund and little likelihood of staying in business at all.