Paradox involves a statement that is apparently contradictory, but it really presents a truth. The poet Marianne Moore uses a paradox in "Nevertheless" when she declares, "Victory won't come to me unless I go/to it." Paradox is often surprising, or even shocking; therefore, it draws the reader's attention to what is being stated.
In Chapter 2 of Book I of A Tale of Two Cities, in the twentieth indention (counting each line of dialogue as an indention) the paragraph containing a paradox begins with this sentence:
The stillness consequent on the cessation of the rumbling and labouring of the coach, added to the stillness of the night, made it very quiet indeed.
Further, this paragraph reads,
The hearts of the passengers beat loud enough perhaps to be heard; but at any rate, the quiet pause was audibly expressive of people out of breath, and holding that breath, and having the pulses quickened by expectation.
Here lies the paradox: a "quiet pause" cannot really be heard, or "audible." But, the truth of this contradiction is that when the listener notices the "pause" of the passengers, the silence would be noticeable--"audible" to his mind.