A paradox is a seemingly contradictory statement that actually points to a greater truth when closely examined. In "In a Dark Time" the speaker uses paradox to demonstrate themes relating to identity and self-awareness.
The opening line of this poem is a well-known example of paradox:
In a dark time, the eye begins to see.
At first, it might seem impossible that the speaker "begins" to see in the darkness. It seems much more natural and plausible that sight first appears when sunlight bathes the earth. Yet a different kind of sight happens in darkness, accentuating abilities that are more focused and intentional. When light disappears, the human eye first struggles to find any sense of familiarity. Yet, gradually, forms begin to appear as the eye continues to search through the darkness for points of visual reference.
Metaphorically, the speaker is also referring to the "dark times" of life, when hope seems lost and the path ahead appears impossible. During these times, he finds that his soul begins to "see" more clearly as he meets another version of himself "in the deepening shade."
The opening of the second stanza also utilizes paradox:
What's madness but nobility of the soul
At odds with circumstance?
Typically, madness would not be closely associated with nobility. In fact, most people deemed "mad" by society are considered outcasts and even dangerous. Yet the speaker insists that he stands on the "edge" of sanity, which is simply being "at odds" with the expectations of the world around him. Those who are able to recognize their own madness are therefore able to appreciate the "winding path" to deeper self-awareness.
The speaker begins the final stanza with another example of paradox:
Dark, dark my light ...
The speaker's own mental darkness becomes the source of his strength as he embraces the struggle to determine "Which I is I?" He refuses to be consumed by his own "fear" of mental illness and accepts the struggle of allowing his own mind to "enter itself." Because of this deeper self-awareness, the speaker is also able to welcome God into his mind, and he therefore finds "light" in the midst of darkness.