There is a view that science can ultimately explain everything, can answer every legitimate question. It is called scientism. Interestingly, most scientists consider scientism a pretty dubious doctrine. Many accept there are questions that science has not, and perhaps cannot, answer.

Take moral questions, for example. Is killing always wrong? Is it morally acceptable to design a baby? Science can make new technologies possible, including weapons of mass destruction and genetic engineering. But most scientists agree that science cannot tell us whether it is ever morally permissible to use such technologies. It seems, as the philosopher David Hume famously noted, that science ultimately reveals only what is the case; it cannot tell us what we morally ought or ought not to do.

Nor, it seems, can science explain why the universe itself exists – why there is anything at all. Scientific explanations involve appealing to natural causes or laws. For example, if you ask why the water froze in the pipes last night, a scientist might explain by pointing out that the temperature of the water fell below zero, and that it is a law of nature that water freezes below zero. That would explain why the water froze. But what explains why there are any natural laws or causes in the first place? What explains why there is a natural world at all? Why there is something rather than nothing? Here, it would seem, science cannot provide answers.