His heroic act saved the boy's life.
It is heroic for soldiers to fight for their country.
Kicking in that door was quite a heroic effort.
It depends on whether the statement is a complete sentence or not. If the quoted statement is a complete sentence, you would use a period. If the quoted statement is within a larger sentence, you would use a comma.
Plato is a name, so you use it in a manner consistent with how you would use any other name. As in, "Plato wrote a sentence."
Example sentence - He would profess his love for her all the days of his life.
Example sentence - His time and money would be better spent in philanthropy.
The firefighter's heroic actions saved the family from the burning building.
He received a medal of valor for his heroic actions in battle.
I would have never dreamed that my heroic achievement would result in a sentence. His amazing exploits are consistently topped by other, more grand achievements.
The heroic fireman entered the burning building.
The antagonist of the novel did everything in his power to stop the protagonist's heroic efforts.
The firefighter's action in saving the children from the burning house was heroic.
Kicking in that door was quite a heroic effort.
Many inspiring stories and plays have been written that EXTOL the heroic deeds of Joan of Arc.
After his heroic act, the fireman received the highest encomium that was ever given to a rookie by the Fire Marshall.
The works of Poussin and Lorrain exemplified the use of heroic landscapes.
I would use it correctly in a sentence, of course. Thank you for asking.
Jarry use paroxysm in a sentence.\