Scientific knowledge has its dangers, but so has every great thing. Over and beyond the dangers with which it threatens the present, it opens up as nothing else can, the vision of a possible happy world; a world without poverty, without war, with little illness. Science, whatever unpleasant consequences it may have by the way, is in its very nature a liberator. Which one of the following is the most important implication of the passage?

The passage highlights that despite its dangers, scientific knowledge uniquely "opens up... the vision of a possible happy world." This "vision" refers to an ideal, an aspiration, or a conceived future state. Let's analyze the options: A) A happy world is a dream of science. This option directly aligns with the passage's statement that science "opens up... the vision of a possible happy world." A "vision of a possible world" is essentially an ideal or an aspiration, which can be described as a "dream." Science, through its potential, presents this ideal future. This is a strong implication. B) Science only can build a happy world, but it is also the only major threat. The passage states science "opens up... the vision" of a happy world "as nothing else can," implying its unique role in conceiving this possibility, but it doesn't explicitly state science is the *only* thing that can *build* it. Furthermore, while it acknowledges "dangers," it doesn't claim science is the "only major threat." It says dangers exist, "but so has every great thing," implying other things also pose dangers. This option is too extreme and not fully supported. C) A happy world is not possible without science. The passage states science "opens up as nothing else can, the vision of a possible happy world." This means science is uniquely capable of revealing or conceiving this possibility. While this strongly suggests science is indispensable for the *conception* or *perception* of such a world's possibility, stating it's "not possible without science" is a very definitive claim about the *actualization* or inherent possibility itself. The passage focuses on science providing the *vision* of possibility, which is a subtle but important distinction from being the sole enabler of that possibility. Option A, focusing on the "dream" or "vision," is a more direct interpretation of the passage's emphasis. D) A happy world is not at all possible with or without science. This option directly contradicts the passage, which explicitly states science "opens up... the vision of a *possible* happy world." Conclusion: The most important implication of the passage is that science provides the ideal or aspiration for a happy world. The phrase "vision of a possible happy world" is best captured by the idea of a "dream of science." The final answer is A