Mysterious Answers to Mysterious Questions

Imag­ine look­ing at your hand, and know­ing noth­ing of cells, noth­ing of bio­chem­istry, noth­ing of DNA. You’ve learned some anatomy from dis­sec­tion, so you know your hand con­tains mus­cles; but you don’t know why mus­cles move in­stead of ly­ing there like clay. Your hand is just . . . stuff . . . and for some rea­son it moves un­der your di­rec­tion. Is this not magic?

It seemed to me then, and it still seems to me, most prob­a­ble that the an­i­mal body does not act as a ther­mo­dy­namic en­g­ine . . . The in­fluence of an­i­mal or veg­etable life on mat­ter is in­finitely be­yond the range of any sci­en­tific in­quiry hith­erto en­tered on. Its power of di­rect­ing the mo­tions of mov­ing par­ti­cles, in the demon­strated daily mir­a­cle of our hu­man free-will, and in the growth of gen­er­a­tion af­ter gen­er­a­tion of plants from a sin­gle seed, are in­finitely differ­ent from any pos­si­ble re­sult of the for­tu­itous con­course of atoms[.]1

[C]on­scious­ness teaches ev­ery in­di­vi­d­ual that they are, to some ex­tent, sub­ject to the di­rec­tion of his will. It ap­pears, there­fore, that an­i­mated crea­tures have the power of im­me­di­ately ap­ply­ing, to cer­tain mov­ing par­ti­cles of mat­ter within their bod­ies, forces by which the mo­tions of these par­ti­cles are di­rected to pro­duce de­sired me­chan­i­cal effects.2

Modern biol­o­gists are com­ing once more to a firm ac­cep­tance of some­thing be­yond mere grav­i­ta­tional, chem­i­cal, and phys­i­cal forces; and that un­known thing is a vi­tal prin­ci­ple.3

—Lord Kelvin

This was the the­ory of vi­tal­ism ; that the mys­te­ri­ous differ­ence be­tween liv­ing mat­ter and non-liv­ing mat­ter was ex­plained by an Élan vi­tal or vis vi­talis. Élan vi­tal in­fused liv­ing mat­ter and caused it to move as con­sciously di­rected. Élan vi­tal par­ti­ci­pated in chem­i­cal trans­for­ma­tions which no mere non-liv­ing par­ti­cles could un­dergo—Wöh­ler’s later syn­the­sis of urea, a com­po­nent of urine, was a ma­jor blow to the vi­tal­is­tic the­ory be­cause it showed that mere chem­istry could du­pli­cate a product of biol­ogy.

Cal­ling “Élan vi­tal” an ex­pla­na­tion, even a fake ex­pla­na­tion like phlo­gis­ton, is prob­a­bly giv­ing it too much credit. It func­tioned pri­mar­ily as a cu­ri­os­ity-stop­per. You said “Why?” and the an­swer was “Élan vi­tal!”

When you say “Élan vi­tal!” it feels like you know why your hand moves. You have a lit­tle causal di­a­gram in your head that says:

But ac­tu­ally you know noth­ing you didn’t know be­fore. You don’t know, say, whether your hand will gen­er­ate heat or ab­sorb heat, un­less you have ob­served the fact already; if not, you won’t be able to pre­dict it in ad­vance. Your cu­ri­os­ity feels sated, but it hasn’t been fed. Since you can say “Why? Élan vi­tal!” to any pos­si­ble ob­ser­va­tion, it is equally good at ex­plain­ing all out­comes, a dis­guised hy­poth­e­sis of max­i­mum en­tropy, et cetera.

But the greater les­son lies in the vi­tal­ists’ rev­er­ence for the Élan vi­tal, their ea­ger­ness to pro­nounce it a mys­tery be­yond all sci­ence. Meet­ing the great dragon Un­known, the vi­tal­ists did not draw their swords to do bat­tle, but bowed their necks in sub­mis­sion. They took pride in their ig­no­rance, made biol­ogy into a sa­cred mys­tery, and thereby be­came loath to re­lin­quish their ig­no­rance when ev­i­dence came knock­ing.

The Se­cret of Life was in­finitely be­yond the reach of sci­ence! Not just a lit­tle be­yond, mind you, but in­finitely be­yond! Lord Kelvin sure did get a tremen­dous emo­tional kick out of not know­ing some­thing.

But ig­no­rance ex­ists in the map, not in the ter­ri­tory. If I am ig­no­rant about a phe­nomenon, that is a fact about my own state of mind, not a fact about the phe­nomenon it­self. A phe­nomenon can seem mys­te­ri­ous to some par­tic­u­lar per­son. There are no phe­nom­ena which are mys­te­ri­ous of them­selves. To wor­ship a phe­nomenon be­cause it seems so won­der­fully mys­te­ri­ous is to wor­ship your own ig­no­rance.

Vi­tal­ism shared with phlo­gis­ton the er­ror of en­cap­su­lat­ing the mys­tery as a sub­stance. Fire was mys­te­ri­ous, and the phlo­gis­ton the­ory en­cap­su­lated the mys­tery in a mys­te­ri­ous sub­stance called “phlo­gis­ton.” Life was a sa­cred mys­tery, and vi­tal­ism en­cap­su­lated the sa­cred mys­tery in a mys­te­ri­ous sub­stance called “Élan vi­tal.” Nei­ther an­swer helped con­cen­trate the model’s prob­a­bil­ity den­sity—helped make some out­comes eas­ier to ex­plain than oth­ers. The “ex­pla­na­tion” just wrapped up the ques­tion as a small, hard, opaque black ball.

In a com­edy writ­ten by Moliére, a physi­cian ex­plains the power of a so­porific by say­ing that it con­tains a “dor­mi­tive po­tency.” Same prin­ci­ple. It is a failure of hu­man psy­chol­ogy that, faced with a mys­te­ri­ous phe­nomenon, we more read­ily pos­tu­late mys­te­ri­ous in­her­ent sub­stances than com­plex un­der­ly­ing pro­cesses.

But the deeper failure is sup­pos­ing that an an­swer can be mys­te­ri­ous. If a phe­nomenon feels mys­te­ri­ous, that is a fact about our state of knowl­edge, not a fact about the phe­nomenon it­self. The vi­tal­ists saw a mys­te­ri­ous gap in their knowl­edge, and pos­tu­lated a mys­te­ri­ous stuff that plugged the gap. In do­ing so, they mixed up the map with the ter­ri­tory. All con­fu­sion and be­wil­der­ment ex­ist in the mind, not in en­cap­su­lated sub­stances.

This is the ul­ti­mate and fully gen­eral ex­pla­na­tion for why, again and again in hu­man­ity’s his­tory, peo­ple are shocked to dis­cover that an in­cred­ibly mys­te­ri­ous ques­tion has a non-mys­te­ri­ous an­swer. Mys­tery is a prop­erty of ques­tions, not an­swers.

There­fore I call the­o­ries such as vi­tal­ism mys­te­ri­ous an­swers to mys­te­ri­ous ques­tions.

Th­ese are the signs of mys­te­ri­ous an­swers to mys­te­ri­ous ques­tions:

  • First, the ex­pla­na­tion acts as a cu­ri­os­ity-stop­per rather than an an­ti­ci­pa­tion-con­trol­ler.

  • Se­cond, the hy­poth­e­sis has no mov­ing parts—the model is not a spe­cific com­plex mechanism, but a blankly solid sub­stance or force. The mys­te­ri­ous sub­stance or mys­te­ri­ous force may be said to be here or there, to cause this or that; but the rea­son why the mys­te­ri­ous force be­haves thus is wrapped in a blank unity.

  • Third, those who proffer the ex­pla­na­tion cher­ish their ig­no­rance; they speak proudly of how the phe­nomenon defeats or­di­nary sci­ence or is un­like merely mun­dane phe­nom­ena.

  • Fourth, even af­ter the an­swer is given, the phe­nomenon is still a mys­teryand pos­sesses the same qual­ity of won­der­ful in­ex­pli­ca­bil­ity that it had at the start.


Lord Kelvin, “On the Dis­si­pa­tion of En­ergy: Ge­ol­ogy and Gen­eral Physics,” in Pop­u­lar Lec­tures and Ad­dresses, vol. ii (Lon­don: Macmil­lan, 1894).


Lord Kelvin, “On the Me­chan­i­cal ac­tion of Heat or Light: On the Power of An­i­mated Crea­tures over Mat­ter: On the Sources available to Man for the pro­duc­tion of Me­chan­i­cal Effect,” Pro­ceed­ings of the Royal So­ciety of Ed­in­burgh 3, no. 1 (1852): 108–113.


Sil­vanus Phillips Thomp­son, The Life of Lord Kelvin (Amer­i­can Math­e­mat­i­cal So­ciety, 2005).