Insurance has been defined in many different ways. Willett, for example, has defined it as "that social device for making accumulations to meet uncertain losses of capital which is carried out through the transfer of the risks of many individuals to one person or to a group of persons." Kulp states that "insurance is a formal social device for the substitution of certainty for uncertainty through the pooling of hazards." In the same vein, Riegel and Miller say that from a functional standpoint, "insurance is a social device whereby the uncertain risks of individuals may be combined in a group and thus made more certain, small periodic contributions by the individuals providing a fund out of which those who suffer loss may be reimbursed." Finally, Pfeffer, in his search for a generic definition, concludes that "insurance is a device for the reduction of the uncertainty of one party, called the insured, through the transfer of particular risks to another party, called the insurer, who offers a restoration, at least in part, of economic losses suffered by the insured."