Though difficult, this ascertainment is not impossible. The problem is to be dealt with in the same manner that we should estimate a family in which there are persons of every condition from infancy to old age. Each member of it tends to pursue a definite course, though some, cut off in an untimely manner, may not complete it. One may be enfeebled by accident, another by disease; but each, if his past and present circumstances be fully considered, will illustrate the nature of the general movement that all are making. To demonstrate that movement most satisfactorily, certain members of such a family suit our purpose better than others, because they more closely represent its type, or have advanced farthest in their career. [Sidenote: The intellectual class the true representative of a community.] So in a family of many nations, some are more mature, some less advanced, some die in early life, some are worn out by extreme old age; all show special peculiarities. There are distinctions among kinsmen, whether we consider them intellectually or corporeally. Every one, nevertheless, illustrates in his own degree the march that all are making, but some do it more, some less completely. The leading, the intellectual class, is hence always the true representative of a state. It has passed step by step through the lower stages, and has made the greatest advance. [Sidenote: Interstitial change and death the condition of individual life.] In an individual, life is maintained only by the production and destruction of organic particles, no portion of the system being in a state of immobility, but each displaying incessant change. Death is, therefore, necessarily the condition of life, and the more energetic the function of a part--or, if we compare different animals with one another--the more active the mode of existence, correspondingly, the greater the waste and the more numerous the deaths of the interstitial constituents. [Sidenote: Particles in the individual answer to persons in the state.] To the death of particles in the individual answers the death of persons in the nation, of which they are the integral constituents. In both cases, in a period of time quite inconsiderable, a total change is accomplished without the entire system, which is the sum of these separate parts, losing its identity. Each particle or each person comes into existence, discharges an appropriate duty, and then passes away, perhaps unnoticed. The production, continuance, and death of an organic molecule in the person answers to the production, continuance, and death of a person in the nation. Nutrition and decay in one case are equivalent to well-being and transformation in the other. [Sidenote: Epochs in national the same as in individual life.]