What are the three types of oratory?

John Quincy Adams, answered from the texts and cited to the page.

John Quincy Adams answers

The ancients established three kinds, and the division holds because it rests not on convention but on the nature of the occasions themselves. Demonstrative oratory is that species of public speaking which consists of discourses formally prepared and delivered in celebration of some person or public event; praise or censure is its ultimate object, honor and shame the hinges upon which it revolves.

Its application is only to the opinions of the audience — it leads to no vote, verges to no verdict, and may be considered complete in itself. Deliberative oratory is the eloquence of assemblies, and its characteristic common measure is utility.12 Deliberation presupposes a freedom of election in the deliberating body; the issue is action, and the final determination of what that action shall be results from a sense of expediency entertained by the speaker's audience.34

It is in deliberative oratory alone that eloquence and the art of persuasion may be considered terms perfectly synonymous, for the orator's task is to act directly upon the will of his hearers.5 Cicero assigned to it the place of highest importance among the three kinds — an arrangement suited to all republican governments, and to ours above all, where deliberative assemblies are more numerous than anywhere the ancients knew. Judicial oratory manages the litigation of causes public or private, civil or criminal, in the courts of justice — in other words, it is the eloquence of the bar.6

Its central point, to which all argument converges, is justice; and Cicero, who had practiced all three, assigned to judicial eloquence the place of highest difficulty.78 The French rhetoricians, and after them Blair, substituted a division into the eloquence of the pulpit, of popular assemblies, and of the bar.9 Two of those three are merely other names for the deliberative and the judicial; but in omitting the demonstrative altogether they left a numerous and, in our country, an important class of public discourses entirely without a name — for we have resumed in these United States that particular style of speaking, so customary among the Greeks and Romans, which in Britain is almost entirely unpractised.10

Sources

  1. Demonstrative oratory, I informed you, was that species of public speaking, which consists of discourses, formally prepared, and delivered in celebration of some person or public event... That praise or censure was its ultimate object; honor and shame the hinges, upon which it revolved.
    Lectures on Rhetoric and Oratory, Vol 1
  2. Demonstrative orations terminate in themselves. They lead to no vote; they verge to no verdict. The drift of the discourse is to display the merits of the subject, and the talents of the speaker.
    Lectures on Rhetoric and Oratory, Vol 1
  3. the characteristic common measure of this class is utility.
    Lectures on Rhetoric and Oratory, Vol 1
  4. Deliberation presupposes a freedom of election in the deliberating body. It presupposes alternatives, which may be adopted or rejected. The issue of deliberation is action, and the final determination, what that action shall be, results from a sense of utility or expediency, entertained by the speaker's audience.
    Lectures on Rhetoric and Oratory, Vol 1
  5. It is in deliberative oratory, and in that alone, that eloquence and the art of persuasion may be considered, as terms perfectly synonymous.
    Lectures on Rhetoric and Oratory, Vol 1
  6. Cicero has assigned to judicial eloquence the place of the highest difficulty, and to the eloquence of deliberation that of the highest importance. This arrangement is suited to all republican governments, and indeed to all governments, where the powers of legislation are exercised by a deliberative assembly.
    Lectures on Rhetoric and Oratory, Vol 1
  7. Judicial oratory manages the litigation of causes public or private, civil or criminal, in the courts of justice. In other words it is the eloquence of the bar.
    Lectures on Rhetoric and Oratory, Vol 1
  8. the central point, to which all the rays of argument should converge, in deliberative oratory is utility; in judicial discourses is justice; and in demonstrative orations is praise or censure.
    Lectures on Rhetoric and Oratory, Vol 1
  9. The modern arrangement, adopted by the French rhetoricians, and after them by Blair, is into the eloquence of the pulpit, of popular assemblies, and of the bar.
    Lectures on Rhetoric and Oratory, Vol 1
  10. in excluding this latter denomination altogether, they have left a numerous and in our country an important class of public discourses entirely destitute of a name... we have resumed in these United States that particular style of speaking, which was so customary among the Greeks and Romans, but which in the island of Great Britain seems to be almost entirely unpractised.
    Lectures on Rhetoric and Oratory, Vol 1