| > It is possible to explain what is happening without explaining how. That's a description -- an account of what was observed. By definition, an explanation must add something to a description. "The night sky is filled with points of light." -- a description. "Those points are distant thermonuclear furnaces, powered by atomic fusion." -- an explanation. "Similar bird species have differently shaped beaks." -- a description. "Bird species evolve traits that confer a survival advantage in their distinct environments." -- an explanation. > It is possible to know that A causes B without knowing why ..." One cannot claim to know that A causes B without also knowing why, otherwise puddles cause rain. Science is not merely about knowing -- it's about knowing that we know. An observation asserts a fact without context. A scientific theory offers more than mere description, and its standing rests solely on the fact that it has resisted falsification. > To give an example, we know that mass causes gravitational attraction even though we don't fully understand the mechanism that causes it. Yes, but that's not a scientific theory, it's a description -- mass causes gravitational attraction, or equivalently, gravitational attraction causes mass (my point is the claim is wrong but without a theory, we can't know that it's wrong). As long as there's no testable theory, the two descriptions are equivalent. The Greeks believed our sight resulted from our eyes shooting beams out into the environment. Until we had a testable theory, no one could reasonably dispute that idea. A theory is not a description -- it offers more than an account of observed facts. The water rises across the beach over a period of hours: a description. The sun and moon apply tidal forces -- a spatial differential in gravitational force -- to the water, causing it to periodically rise and fall: an explanation, one that can be tested and potentially falsified. |