What concept suggests that humans can never fully comprehend all of existence?

The concept that suggests humans can never fully comprehend all of existence is most closely aligned with existentialism, as it grapples with the absurdity and complexity of life. Existentialism emphasizes the limitations of human understanding and the individual’s search for meaning in an often incomprehensible universe. This philosophical approach recognizes that while we may strive to find answers and create meaning, the totality of existence remains elusive and beyond complete human grasp.

The other options, while interesting, do not capture this idea as directly. The Butterfly Effect refers to a concept in chaos theory where small changes can lead to significant events, but it does not specifically comment on human comprehension. Overreaching implies attempting to go beyond one’s capabilities, which could relate, but does not encapsulate the inherent limitations of understanding existence itself. The Great White Whale, a symbol from Melville's "Moby Dick," represents obsession and the unattainable but does not define a broader philosophical concept about comprehension of existence. Thus, existentialism stands out as the most fitting choice for conveying the idea of humanity's struggle with understanding the vastness of existence.