Science is Never Certain. So Why Should We Trust It?

If we wait for scientific proof before we act, we’ll never move a muscle or make any important decisions

When one admits that nothing is certain one must, I think, also add that some things are more nearly certain than others.
— Bertrand Russell, philosopher and mathematician

When I wrote recently about the potential risks of marijuana — and there are several — I noted an important caveat: “We lack firm conclusions on a lot of this.” A sharp reader highlighted the passage and asked two perfectly reasonable questions: “What’s the point of sharing all this information if none of the studies or data are confirmed? Doesn’t this seem like an irresponsible way to spread information?”

My response (below) speaks to a cold hard truth: Science never proves anything beyond all doubt.

That does not mean an inconclusive body of research is useless. Far from it. It just means that the state of understanding on a given topic might range from modest to solid to near certainty, but not absolute proof (which is why we science journalist use words like suggests or shows or indicates instead of proves). It means we might (or might not) have enough good information to act upon. It means we can expect to learn more.