True health: How we know

In my work and my world, I am dealing routinely with whiplashinducing headlines about health, and nutrition in particular (“no, wait, fruits and vegetables are bad for us this week!”) that raise questions about science, sense and knowledge. When whatever we think we know, however reliably we think we know it, is called into question so routinely, it begs the question: how do we know?

My question is not how we know any given thing, but rather how do we know anything, ever, at all? The surprising answer is, we do not. Not unless we decide to trust our nervous systems and the perceptions they engender, for which there is a compelling case.

We do not, truly, know anything because all we can do is perceive. Were we in a virtual reality, like the one portrayed in the science fiction classic, The Matrix, we would likely be unable to know it, or prove it. We cannot disprove it now, either, since all of our perceptions of all of our disproofs would take place in the same virtual reality, reinforce it and do nothing to tell us it wasn’t real.

We really can’t know anything for sure. But we can choose to have faith in the veracity of our impressions here, and build knowledge from them. If our perceptions are reliable, then what we derive from them is reliable, and so, too, are the embellishments of science, which are, essentially, extensions of our native perceptions via instruments and assays, lenses and equations.

It makes sense that our nervous systems and perceptions would be reliable since they are the ones we have here, wherever here is, and thus they are the ones adapted to be here. They are the perceptions that help us survive in this place where we are surviving.

We can, in effect, choose to have faith in our perceptions, and build our understanding from that foundation. The only alternative is to renounce the reliability of the only reality we know, and never understand anything. Most of us have made the choice long ago, if rather unconsciously.

What an intriguing, if ironic opportunity for bridge-building to concede that the origins of science reside in faith. Not faith in supernatural forces; faith in ourselves, faith in our perceptions, faith in our capacity to know — but faith, just the same. Knowledge and knowing do not begin with science, but with our faith in the reliability of constant or consistent patterns we perceive in the world around us. Knowing begins with our senses, and the common sense to trust them.

Science, then, extends those perceptions, dispels the denser shadows reveals the hidden. But there is nothing an electron microscope or the Hubble telescope could show us that would remedy lack of trust in our native capacity to see. Science expands the realm of what we can know, only because knowing is possible in the first place, based on patterns we perceive in the world around us. The more constant the patterns, the more reliable — or even certain — our knowledge.

How we know is of practical importance to us every day, for science is being abused. The science of climate change is abused by deniers of the long established and increasingly obvious, an indictment succinctly and elegantly made recently by one of our premier scientists, astrophysicist Neil deGrasse Tyson. The science of nutrition and health is abused every time a new round of headlines tell us everything we knew most reliably until yesterday, such as the general benefits of eating vegetables and fruits and legumes, is wrong again.

We did not suspect, we knew that apples fell down, not up from their trees before Newton. Had Newton’s calculations said otherwise, Newton’s formulas and not the apples would have been wrong. So, too, we know that a passing fixation on lectins does nothing to alter the established benefits of routine consumption of vegetables, fruits and legumes; nor does a study overlooking the encompassing influence of social factors and environmental circumstance on health.

Science cannot tell us that apples fall up out of trees, or that fire puts out water — for these are established as false where knowledge begins, in the realm of our native perceptions.

Science, for all its independent marvels, depends on sense. Science is a powerful tool, and like any other power tool, can be used well or badly. For it to foster understanding rather than constant confusion in this age of alternative and competing “truths” on every important topic, we need to use it more sensibly.

This column follows a talk I was privileged to give recently to students in a Theory of Knowledge course at the Cheshire Academy taught by Mr. Chip Boyd. My thanks to Mr. Boyd, and his students, for the provocation!

Science, for all its independent marvels, depends on sense. Science is a powerful tool, and like any other power tool, can be used well or badly.