The mystery of life? I don’t know

Originally published 12 September 2004

Albert Ein­stein said, “The­o­ries should be as sim­ple as pos­si­ble, but no simpler.”

At first glance, this may sound like a Zen koan, or a para­dox. In fact, it is a pro­found state­ment that says more than vol­umes of philosophy.

But first, a bit of background.

From the dawn of time, peo­ple have resist­ed say­ing “I don’t know.” They looked instead for expla­na­tions in trib­al tra­di­tion, sacred books, or the sup­posed wis­dom of shamans, priests, and prophets.

The most com­mon cov­er-up for igno­rance is to invoke divin­i­ty. A storm that dev­as­tates a vil­lage is “an act of God.” A child tak­en by dis­ease at a young age is divine pun­ish­ment for a par­en­t’s sin. And so on.

Super­sti­tions too have their ori­gin as a cov­er for igno­rance. I lost my wal­let because a black cat crossed my path. My lover left me because Venus was in the wrong house of the zodi­ac. I won at the roulette table because I was hold­ing my lucky rab­bit’s foot.

In every case a reluc­tance to say, “I don’t know.” No admis­sion that the cause of an event might be unknown or unknowable.

Tra­di­tion­al­ly, peo­ple have divid­ed expla­na­tions into true and false. In gen­er­al, truth is what we believe. False­hood is what every­one else believes, if different.

Ein­stein’s remark sug­gests anoth­er atti­tude towards knowledge.

On the one hand, we have reli­able the­o­ries, char­ac­ter­ized by the sim­plic­i­ty with which they explain expe­ri­ence. Not absolute truths, but pro­vi­sion­al truths that work well for the time being and are open to revision.

For exam­ple, New­ton’s the­o­ry of grav­i­ty qual­i­fies as reli­able knowl­edge because of the way a few sim­ple equa­tions explain every­thing from the motion of plan­ets, to the fall of an apple, to the flow of the tides. With New­ton’s equa­tions we can pre­dict the return of a comet — Hal­ley’s Comet, say — to the day, hour, sec­ond, hun­dreds of years in advance. That’s reli­able knowledge.

The the­o­ry of evo­lu­tion by nat­ur­al selec­tion explains with almost self-evi­dent sim­plic­i­ty the diver­si­ty and inter­re­lat­ed­ness of life on Earth as revealed in the fos­sil record and in the genes. That’s reli­able knowledge.

That’s knowl­edge as sim­ple as we can make it.

Beyond that, accord­ing to Ein­stein, we must be hum­ble enough to say “I don’t know.”

Those three lit­tle words, “I don’t know,” are com­plete­ly mod­ern. They are the essence of the sci­en­tif­ic way of know­ing, and they set the per­son of sci­en­tif­ic tem­pera­ment apart from every oth­er peo­ple who have gone before — and from most peo­ple who are alive today.

Beneath reli­able knowl­edge Ein­stein draws a line. Don’t sup­pose we know what we don’t know, he sug­gests. Don’t make up fic­tions — gods, spir­its, super­sti­tions, the influ­ence of the stars, lucky charms — to explain things for which we have as yet no reli­able explanation.

As sim­ple as pos­si­ble, but not simpler.

The physician/essayist Lewis Thomas wrote: “The great­est of all the accom­plish­ments of 20th-cen­tu­ry sci­ence has been the dis­cov­ery of human igno­rance.” He was talk­ing about the recog­ni­tion that there is an entire uni­verse below Ein­stein’s bot­tom line about which we know noth­ing, and about which we should be will­ing to admit that we know nothing.

Those three lit­tle words — “I don’t know” — are used far too infre­quent­ly by teach­ers, politi­cians, reli­gious lead­ers, even philoso­phers. With the pre­sump­tion of knowl­edge where no reli­able knowl­edge exists goes right­eous­ness. Right­eous­ness breeds pogroms, jihads, and cru­sades. Right­eous­ness flies air­planes into sky­scrap­ers and holds chil­dren hostage in schools. Right­eous­ness pre­sumes to forcibly impose on oth­ers what we think they want or need.

If sci­ence has giv­en one great gift to the world — greater than the won­ders of tech­nol­o­gy, greater than mod­ern med­i­cine, greater than flights to the moon and plan­ets — it has giv­en us per­mis­sion to say “I don’t know.”

How did life evolve from non-life? I don’t know. What is con­scious­ness? I don’t know. What start­ed the big bang? I don’t know. Why did my father die at a rel­a­tive­ly young age of can­cer? I don’t know. Why do bad things hap­pen to good peo­ple? I don’t know.

As sim­ple as pos­si­ble, but no sim­pler. Iron­i­cal­ly, it is when we give up think­ing we know it all that we begin to acquire reli­able knowledge.

When we think we know every­thing, think­ing stops.