"Attempting to harness the engine of our own destruction...only humans are so foolish" is a line spoken by by Major Misato Katsuragi in the series Neon Genesis Evangelion. She speaks the line late in the series, when one of the first big secrets is revealed. Although the plot of Evangelion is almost incomprehensible to explain, I will attempt to explain the quote anyway: Major Katsuragi has just learned that the Evangelion units, previously believed to be mechanical, are actually biological in nature, and cloned from Adam, an alien being (who is kept in stasis on a crucifix buried deep underground). The irony is that the Evangelion units are meant to fight other beings like Adam, referred to as Angels. It is later revealed that the entity that everyone, including Katsuragi, believes to be Adam is actually Lilith, the original mother of humanity.
And yes, I realize what that sounds like. And that is the summary, too. The complete story is more complicated. I wouldn't be writing about this quote if it was just a line describing the aliens and robots of a science fiction series. But Evangelion is another story, a story of angst, sometimes carried to a ridiculous height. The science fiction story and the story of human fragility and madness are meant to be parallel stories, and this quote is about both of them. One of the basic psychological and metaphysical concepts in Evangelion is that the basis of human consciousness and existence as an individual identity is based on an experience of separateness and emptiness. However, this separation causes an anxiety in people, which they attempt to fill.
I think this quote is equally a reference to that. People's knowledge of the world and as themselves as separate entities is what causes them pain, and yet they use this same knowledge to try to strengthen their ego and overcome this pain, which (as Neon Genesis Evangelion suggests in its long series of affairs, betrayals and suicides) only adds more to the pain. The engine of separate consciousness can never overcome the destruction of separate consciousness.
This explanation is strengthened by a close reading of the rather ornate kabalistic symbolism used in Evangelion. In the series, it is revealed that the Angels are a race that selected to eat from the Tree of Life, while humans ate from the Tree of Knowledge. So while Major Katsuragi's statement is in one way wrong, (The Evangelion units are made from the progenitor of humanity, not of the Angels), she is in another way right, because it was the fruit of knowledge, inherited from Lilith that led humanity to a fragmented existence, where they would vainly seek to overcome their anxiety.