There are a lot of ways to define science. The broadest might characterize it as a systematic process for uncovering facts or explanations about the way the world works. From there, individual scientists sometimes differ over the exact features that distinguish science from other enterprises, but they all tend to accept the basic proposition that it is an empirical enterprise. The degree of agreement between theory and observation is what ultimately decides whether a scientific idea offers a good or bad explanation of natural phenomena.
This is why science is often depicted as a naturalistic enterprise. Which is true, but there are different strains of naturalism. It’s worth taking a moment to distinguish them. First, there is metaphysical or ontological naturalism. This is the view that the universe is entirely of matter or other measurable stuff, governed exclusively by natural forces. This stands in contrast to methodological naturalism. Advocates of methodological naturalism grant that the universe may be filled with or influenced by supernatural or immaterial forces, but stipulate that those are irrelevant to science.
Both ideas have their weaknesses. In The Big Picture, Sean Carroll introduces the concept of poetic naturalism as a way of getting around them. Poetic naturalism (PE) grants breathing room for concepts that don’t necessarily relate to the steely, unforgiving rudiments of physical reality. It is traditional naturalism’s less conservative, more ecumenical progeny. PE grants room for higher order concepts like consciousness and protons in a world populated by more fundamental stuff. It even allows room for the “supernatural”, so long as it produces some measurable effect and offers some explanatory merit.