A simple model can help us filter what we learn to determine what is true. The model is the scientific method. The truthfulness of information depends on how well it explains what we observe and its usefulness in achieving outcomes. The better it works, the more likely it is to be true.

The validity of a scientific theory rests on observations. Experiments and observations either support or disprove a theory. A good theory does a more reliable job explaining and predicting what is observed. The better the explanation and the better observations match the theory, the more we believe the theory to be true. We can use reason, observations, and data to test the veracity of what we learn.

Science is never settled. Human capacity to observe and comprehend the world is imperfect. Gaining knowledge is process with no end point. Success is getting better at each step.

Newton’s laws were considered true because they explained and accurately predicted how physical objects behave. In time experiments showed that Newton’s laws weren’t perfect and we inaccurate in some circumstances. New theories (relativity and quantum mechanics) were proposed and proved to more accurate in areas where Newton’s laws fell short. One theory supplants another based on the data and it explanatory and predictive power. Our understanding of the world keeps getting better, but it is never settled and unalterable. What we consider true is the best available now. Better theories may emerge in the future.

The same approach can be used to determine the truth of information relevant to how to live. The questions to ask are: “Does it work in achieving desired outcomes?”; and “Does it work better than alternatives.” Evidence can be gathered to test what is learned. We can use the information and see if is reliable in predicting outcomes. It may be difficult to have the double-blind tests that you find in science. But less rigorous observation and reason can validate or invalidate what we have learned.

Let’s look at an example. Perhaps we recall our parents telling us the “honesty is the best policy.” Or we read Kant’s categorical imperative — only act in a way we would compel everyone else to act — where telling the truth is the standard example.

Should we accept this guidance (always tell the truth) as true and live our lives accordingly? We could formulate some questions, or hypothesis, to test. Could the world function if people lied much of the time? Are people who tell the truth happier than those who lie? How are people who lie viewed by others and does this make the liars lives better or worse? Do societies with a reputation of being honest do better than ones where dishonesty is common? In our own life, do we do better when we are honest or when we lie? Then we can use logic and evidence to answer these questions.

In this example, I believe logic and the preponderance of evidence supports the validity of the moral guidance to tell the truth. It is not perfect. There can be reasons to lie under unusual circumstances. But as a general principle to live by it stands up. It works.