Parallelism has two literary meanings: stating two ideas using the same grammatical structure, or presenting two ideas as if they are equally important. The most famous example of parallelism in Henry's address is the ending, in which he states:
Give me liberty or give me death.
We note that both sides of the "or" that acts as a fulcrum for the clause have exactly the same grammatical construction: the two-word command "give me." Second, the utterance balances two choices (ideas) that Henry assigns equal weight: liberty and death.
Another example of parallelism is in the following:
I consider it as nothing less than a question of freedom or slavery.
Here, it is two ideas that are paralleled: freedom and slavery. These two ideas are antithetical and yet given equal weight. For Henry, there is no middle ground.
Logos is using appeals to logic through facts and statistics. In the following quote, Henry uses the logic (fact) that the colonies already are at war with Great Britain to argue in favor of Virginia joining the war effort. It is hard to argue with what is no longer theory, but reality. He states:
The war is actually begun! ... Our brethren are already in the field! Why stand we here idle?
Pathos is emotional appeal. Most of Henry's argument is emotional. One example is below:
Three millions of people, armed in the holy cause of liberty, and in such a country as that which we possess, are invincible by any force which our enemy can send against us.
This makes no logical sense: of course the Americans can be defeated, and logic would say going up against a superpower like Great Britain guarantees defeat. Therefore, Henry appeals to the idea that the American cause of "liberty" is "holy" and therefore will be protected by God—an emotional appeal to an already longstanding tradition of American exceptionalism. Many times in world history, this same appeal to holiness has led to disaster.