A declamation is an oratorical speech in the first person "I" that inveighs (protests) against something the speaker or writer of the declamation has strong feelings about. The Romans are the originators of the declamation and are the most celebrated in the rhetorical art of declamation. In Rome, Seneca the Elder was the most most closely associated with declamation, which is a form that gives great authority to the author of the declamatory speech.
Justice Oliver Wendall Holmes Jr. is famous for certain declamatory speeches he delivered. One is his 1884 Memorial Day Speech In Our Youth Our Hearts Were Touched With Fire. Another of his famous declamations is his 1895 The Soldier's Faith speech.
Here is an excerpt from In Our Youth Our Hearts Were Touched With Fire.
In Our Youth Our Hearts Were Touched With Fire
Oliver Wendell Holmes, Jr. 1884
When it was felt so deeply as it was on both sides that a man ought to take part in the war unless some conscientious scruple or strong practical reason made it impossible, was that feeling simply the requirement of a local majority that their neighbors should agree with them? I think not: I think the feeling was right-in the South as in the North. I think that, as life is action and passion, it is required of a man that he should share the passion and action of his time at peril of being judged not to have lived.
If this be so, the use of this day is obvious. It is true that I cannot argue a man into a desire. If he says to me, Why should I seek to know the secrets of philosophy? Why seek to decipher the hidden laws of creation that are graven upon the tablets of the rocks, or to unravel the history of civilization that is woven in the tissue of our jurisprudence, or to do any great work, either of speculation or of practical affairs? I cannot answer him; or at least my answer is as little worth making for any effect it will have upon his wishes if he asked why I should eat this, or drink that. You must begin by wanting to. But although desire cannot be imparted by argument, it can be by contagion. Feeling begets feeling, and great feeling begets great feeling. We can hardly share the emotions that make this day to us the most sacred day of the year, and embody them in ceremonial pomp, without in some degree imparting them to those who come after us. I believe from the bottom of my heart that our memorial halls and statues and tablets, the tattered flags of our regiments gathered in the Statehouses, are worth more to our young men by way of chastening and inspiration than the monuments of another hundred years of peaceful life could be.
But even if I am wrong, even if those who come after us are to forget all that we hold dear, and the future is to teach and kindle its children in ways as yet unrevealed, it is enough for us that this day is dear and sacred.
[Read the full speech In Our Youth Our Hearts Were Touched With Fire]