A period is added before an ellipsis to indicate the omission of the end of a sentence, unless the sentence is deliberately incomplete (see 13.53). Similarly, a period at the end of a sentence in the original is retained before an ellipsis indicating the omission of material immediately following the period. What precedes and, normally, what follows the four dots should be grammatically complete sentences as quoted, even if part of either sentence has been omitted. A complete passage from Emerson's essay "Politics" reads:
The spirit of our American radicalism is destructive and aimless: it is not loving; it has no ulterior and divine ends; but is destructive only out of hatred and selfishness. On the other side, the conservative party, composed of the most moderate, able, and cultivated part of the population, is timid, and merely defensive of property. It vindicates no right, it aspires to no real good, it brands no crime, it proposes no generous policy, it does not build, nor write, nor cherish the arts, nor foster religion, nor establish schools, nor encourage science, nor emancipate the slave, nor befriend the poor, or the Indian, or the immigrant. From neither party, when in power, has the world any benefit to expect in science, art, or humanity, at all commensurate with the resources of the nation.
The passage might be shortened as follows:
The spirit of our American radicalism is destructive and aimless. . . . On the other side, the conservative party . . . is timid, and merely defensive of property. . . . It does not build, nor write, nor cherish the arts, nor foster religion, nor establish schools.
Note that the first word after an ellipsis is capitalized if it begins a new grammatical sentence.