On ology S udies 8, 2008 153
Can we speak o i ual na u al kinds?
Lau en iu S aicu
Uni e si y o Bucha es
My alk oday will be abou axonomy and abou he way we classi y hings. Mo e p ecisely,
I will discuss, on he one hand, abou he way we elabo a e ou axonomies in wha
we used o call (despi e Pla o’s wa ning), “ he eal wo ld”, which is he wo ld in which
we b ea h and walk, and, on he o he hand, in he i ual wo ld o he In e ne . Now,
usually, axonomy is a bo ing subjec , i ’s all abou classes, ypes, hie a chies and so on. Bu
some imes, we come o ealize ha as bo ing as i is, i plays a c ucial ole in shaping he
way we see he wo ld a ound us. This was mo e ob ious han e e wi h he deba e ha
ook place las summe (and i ’s s ill going on s ong) be ween he leading as onome s o
he wo ld conce ning he de ini ion o a plane . Tha was indeed a e y busy and exci ing
summe o as onome s! As we know om he news, on Augus 24 2006, a session o
he In e na ional As onomical Union Gene al Assembly in P ague passed a esolu ion
e-de ining he plane s o ou sola sys em. Only 428 o he IAU’s nea ly 10,000 membe s
we e in ol ed in he o e, he news says1. The pa icipan s p oposed a new de ini ion o
a plane . Acco ding o his p oposal, a plane is a celes ial body which sa is y h ee main
condi ions: he objec mus be in o bi a ound a s a , bu mus no i sel be a s a , i mus
ha e enough mass o he body’s own g a i y o pull i in o a nea ly sphe ical shape, and
i mus clea i s o bi o o he objec s. Now, hese h ee condi ions a e easily sa is ied by
he bigge plane s in ou sola sys em, bu no as easily by he es o hem, he smalles
plane s such as Plu o. In ac , acco ding o he o ed de ini ion o a plane , Plu o is no
longe a plane ! So, now he e a e only eigh eal plane s in ou Sola Sys em. Bu no o
wo y, his is no inal! Only a week a e he IAU’s decision s ipped Plu o o i s s a us as a
ull- ledged plane o he Sola Sys em, some “ ebel” as onome s s a ed a campaign wi h
he objec i e o es o ing Plu o’s plane a y s a us. They w o e a pe i ion which was al eady
signed by mo e han 300 p o essional esea che s and which a acks he IAU’s decision.
Thei p o es can be ead on he Web. One o he pe i ion suppo e s said ha he numbe
o hose who o ed in P ague is no enough o such an impo an decision. The IAU
assigned Plu o and o he la ge objec s o a new ca ego y - “dwa plane .”
1 Fo some de ails abou he mee ing see, o example, he ollowing: h p://news.bbc.co.uk/2/
hi/in_dep h/5282440.s m
On ology S udies 8, 2008 154
So, he as onomical axonomy has changed suddenly, by o ing. As I said, he deba e
is no o e ye , maybe he “ ebels” will succeed o es o e he plane a y s a us o Plu o,
maybe hey won’ . Bu ha ’s no he issue I wan o discuss now. I b ough his example
in o discussion because I hink i shows us e y well wo hings: i s , how agile can be
some imes he scien i ic axonomy and, o ha ma e , any o he axonomy, and secondly,
wha a decisi e ole i plays in shaping ou images o he wo ld a ound us.
Now, in alking abou scien i ic axonomy we a e also alking, implici ly, abou na u al
kinds. And ha ’s because mo e o en han no scien i ic axonomies comp ises na u al
kinds o e en s, subs ances, pa icles o hings. In he las decades, he deba e o e he
s a us o na u al kinds gained a signi ican impe us in he philosophical ci cles. The eason
is qui e simple: na u al kinds play a key ole in he ne wo k o scien i ic explana ions.
A e all, scien i ic gene aliza ions and laws a e no abou indi idual hings di ec ly, hey
a e abou kinds o hings ha we ind in na u e, hey a e abou na u al kinds o hings.
Bu hen he ques ion a ise: wha is a na u al kind? This ques ion ecei ed many answe s.
I won’ ollow he de ails o hese answe s because his is no wha I in end o discuss,
bu I will ske ch a b ie axonomy o he mos impo an answe s o e ed. In a i s wa e
o he deba e, he answe s oscilla ed be ween a adical nominalism (na u al kinds a e jus
con en ional classes which a e made acco ding o ou epis emic and p ac ical in e es s) and
a adical ealism (na u al kinds a e na u al classes o hings which we ind as such in na u e).
The ea e , he posi ions aken in he deba e o e he s a us o na u al kinds became mo e
g ada e and, as i always happens in such di icul cases, some mo e easonable answe s
ha e been o mula ed. One o he mos easonable o hese main ained ha na u al kinds
a e dependen upon he na u al p ope ies o hings, p ope ies which exis s as such in
na u e, bu a e well-chosen by us acco ding o ou epis emic o p ac ical in e es s. In his
espec , a e y in e es ing case, which e i ed he deba e o e he s a us o na u al kinds is
ha o biological species. The heo y o e olu ion, maybe he mos impo an biological
heo y, as i is conside ed by many biologis s and philosophe s o biology, is abou species.
Bu , again, he ques ion a ise: wha is a biological species? Is i a na u al kind in he ealis ic
sense?2 O is i a class o indi iduals which we pu oge he in a ce ain way acco ding o ou
explana o y in e es s? Well, he deba e is no o e and, p obably, won’ be o e soon. The
case o Plu o, which I b ough in o discussion ea lie , p obably will gi e a new s imulus o
his deba e o e he on ological s a us o na u al kinds. Now, as I see i , he main di icul y
in his deba e is no a ached o he e m “kind”. This is no a ques ionable e m. We
could all ag ee ha he e m “kind” means “class” o “ ype”, e c. The di icul y a ises once
we ask wha do we mean by “na u al”. Fo he common indi idual, which is unawa e o
philosophical sophis y and a gumen s, “na u al” means wha is ou he e, in na u e, wha
2 Fo a clea exposi ion o he deba e o e he ela ion be ween biological species and na u al
kinds see he monumen al wo k o Alexande Rosenbe g, The S uc u e o Biological Science, Cam-
b idge Uni e si y P ess, 1985, 185-225.
On ology S udies 8, 2008 155
exis s independen ly o us, humans3. On he o he pa , o hose who ead Kan a leas ,
“na u al” could no longe ha e his meaning, “na u al” is only ha which ge s h ough he
il e o ou sensibili y o ou senses. In o he wo ds, “na u al” is only ha which we can
pe cei e. Fu he mo e, o hose who also ead Wi gens ein, “na u al” means ha which
bea , in a way o ano he , he ma k o ou language o , mo e p ecisely, ha which en e
be ween he bounda ies o ou language: a na u al kind is a class o indi iduals which could
be alked abou in language, o which we could gi e a name and a de ini ion4. The e a e, o
cou se, hose who also ead beyond Wi gens ein, o which “na u al” means ha which is
buil up and con igu ed acco ding o ou cul u al no ms, o he opinions o he eli es om
a ce ain epoch and so on. Wha I wan o say wi h his is ha oday, he wo d “na u al”
has no longe a clea meaning, a leas in he philosophical ci cles. Once we abandoned
he cha ac e is ic belie o he obus me aphysical ealism, acco ding o which hings and
en i ies in na u e ha e eal essences, which could be disco e ed by us du ing he cumula i e
p ocess o scien i ic esea ch, we ha e big p oblems in inding some hing which allow us
o speak o “na u al” in he sense o “una ec ed by humans”. And so, i seems all we can
do is o accep ha una oidable ela i ism and o abandon he sophis ica ed deba es o e
he on ological s a us o en i ies such as na u al kinds, e en s, p ope ies, causal powe s
and so on. In he case o na u al kinds, o example, om he ela i is ic poin o iew,
i ou explana o y in e es s and, o cou se, p ac ical in e es s, equi e us o speak abou
he class o mammals as being a na u al kind, we can do his wi hou asking ou sel es i
mammals a e eally a na u al kind o no . Maybe omo ow we will change ou a i ude
and we will abandon he na u al kind o mammals, again, i ou in e es s will equi e his
o i he membe s o he biological science’s eli e will each a consensus in ha di ec ion.
I seems o me ha his posi ion inds i sel a e y well-a icula ed exp ession in Richa d
Ro y’s w i ings, and his is pe haps one o he easons o which Ro y is lo ed and ha ed
by some many people in he same ime5.
Bu e en i his ela i ism migh seem e y appealing ( i s o all, i we emb ace i we
could ge id in a single mo e, o so many philosophical nigh ma es!), I hink we canno
a o d o adop i as such. In his espec , he case o he de ini ion o a plane comes
again on s age. Can we con inue o conside Plu o a plane because we used o do ha
o qui e a ime now? O because he camp o hose who main ain ha i is a plane is
3 This posi ion is o en called “naï e ealism” a label which, al hough wi hou in en ion, makes
a huge injus ice o he long adi ion o me aphysical ealism which is associa ed wi h i . The a gumen s
o me aphysical ealism may be w ong, bu no naï e, in any sense o he wo d.
4 Fo an in e es ing pe spec i e on Wi gens ein’s pe spec i e conce ning he wo ld’s subs a-
um, see Ian P oops, ‘Wi gens ein on he Subs ance o he Wo ld’, Eu opean Jou nal o Philosophy, 12,
1, 2004, 106-126.
5 Fo a e y clea and concise exposi ion o Ro y’s posi ion conce ning he ealism/ ela i ism
deba e see, o example, Richa d Ro y, ‘Pu nam and he ela i is Menace’, The Jou nal o Philosophy,
Vol. XC, 9, 443-461.
On ology S udies 8, 2008 156
bigge han he camp o hei opponen s? And in e sely, can we accep no o conside i
a plane because 428 as onome s decided du ing an o icial mee ing ha i is no a plane ?
I hink he answe is no in bo h cases. And so, wha can we do o , mo e p ecisely, how
a e we supposed o pu an end o his deba e o e he s a us o Plu o o any o he simila
axonomical deba e? We need a basis, a na u al g ound o ancho ing he de ini ion which
conce n us, be i he de ini ion o a plane o o some hing else. And so, we ge back o
he meaning o he e m “na u al”. Bu , as I said ea lie , i is e y di icul o gi e a p ecise
meaning o his e m. I suppose ha anyone who ollowed qui e a bi he deba e o e
he s a us o na u al kinds om he las decades o so could say clea ly enough ha he
s ake in his deba e is p ecisely he meaning o he e m “na u al” and he assigna ion o
an in a ian de ini ion o i . And ha ’s because, e en i we could no longe speak o he
“na u al” in he sense o ha which can be ound ou he e, una ec ed by us, i is equally
impossible o accep ha “na u al” means wha e e we wan i o mean, o wha e e he
cul u al o scien i ical eli es elec s i o mean o wha e e se es be e ou p esen in e es s
and goals. No, we wan o each a de ini ion which could a oid, on he one hand, he
commi men s o ou (human) poin o iew, and on he o he hand o a oid he claim o
mi aculously su passing his poin o iew h ough a di ec pe cep ion o wha could be
ound ou he e, in na u e, wi hou e e ence o ou poin o iew. Bu how can we do
his? Well, I eally don’ know he answe o his ques ion ! Bu in he ollowing I will y
o show ha we could ind new ways o sea ching a easonable answe o his ques ion by
simply compa ing, om he poin o iew o axonomy, he wo wo lds abo e-men ioned:
he eal wo ld a ound us, and he i ual wo ld o he In e ne .
I would like o s a his compa ison by asking wha do we mean by “na u al” in ega d
o wha could be called “ he b a e new wo ld o he In e ne ” ha wo ld in which we all
li e o , o pu i mildly, o which we all pa icipa e, willingly o no , o qui e a ime now?
Mo e p ecisely, how do we disce n be ween na u al and a i icial o con en ional, e c., in
his new ca e which is he In e ne ? Ob iously, an old- ashioned ealis would say ha
his ques ion is plainly absu d o , mo e poli ely, ha i is a ques ion which does no a ise
because he In e ne is comple ely a i ual wo ld which means a i icial. I is jus a human
cons uc ion, a complica ed sequence o 1’s and 0’s, no hing na u al. Bu hen he would
ha e o de ine wha ’s “na u al” and, as I said be o e, he e seems o be no simple de ini ion
o his e m. A e all, o all we know, i could be ha he na u e a ound us o he “ eal
wo ld” is no hing mo e han a complica ed sequence o elemen a y pa icles which we
canno obse e di ec ly no e en wi h he mos sophis ica ed appa a us6. Now, lea ing
aside he educ ionis ques ion o he ul ima e b icks om which he eal wo ld o he
i ual wo ld o he In e ne a e cons uc ed and he analogy be ween hem, he old-
ashioned ealis could con inue by saying ha he di e ence be ween he eal wo ld
6 A good (and en e aining!) in oduc ion o he ‘bes ia y’ o suba omic pa icles is John G ib-
bin’s book In Sea ch o SUSY, Supe symme y and he Theo y o E e y hing, Penguin Books, 1998.
On ology S udies 8, 2008 157
o Na u e and he i ual wo ld o he In e ne lies in he ac ha we canno pe cei e
hings on he In e ne as we pe cei e hings in he eal wo ld. And he would be igh ,
o cou se. We canno ouch he swo d mas e ully handled by a he cha ac e om an
online game which we play on he In e ne , we can only see i on he sc een. Bu he e
a e many hings in he so-called eal wo ld ha we canno ouch, o example we canno
ouch he Pole S a , we can only see i . Yes, he ealis would say, bu in he case o
he In e ne we know ha hose hings we canno ouch bu only see a e made by us, a
cle e p og amme made a ce ain sequence o 1’s and 0’s which in ou eyes appea s
as a shinny swo d in he hand o a legenda y he o. Bu he Pola S a was no made by
us, e en i we can obse e i only h ough he lens o a elescope wi hou being able
o ouch i . This is again ue. Bu i is no su icien : an op ical illusion, o example,
is no some hing made by us, and despi e ha , i is some hing a i icial, a leas in he
sense ha i is no wha i appea s o be. And he abbi hole goes deepe and deepe ,
o bo ow an exp ession o Mo pheus, he amous cha ac e om he equally amous
mo ie The Ma ix. In o he wo ds, his imagina y discussion wi h an equally imagina y
ealis could con inue.
Bu I won’ con inue i because I belie e ha he ealis jus said some hing e y
in e es ing o wha I wan o main ain in he ollowing. He said ha he i ual wo ld o
he In e ne is a wo ld made by us. Mo e impo an s ill is he ac ha i was c ea ed by
us o se e ce ain goals and objec i es. And hese goals and objec i es a e highligh ed
p ecisely by he way in which we cons uc ed he i ual axonomies which popula e he
In e ne and by he way in which hese axonomies a e e ol ing in ime, in p opo ion as
he In e ne is g owing and acqui e new le els. Now, as anyone knows, a leas anyone
who na iga ed on he In e ne a leas once, he In e ne is inhabi ed by many hings:
si es, blogs, po als, i ual o ganiza ions, i ual shops, images, ex s, maps, games,
e c. All hese en i ies a e o ming oge he a ne wo k, e y simila wi h he ne wo k
which compounds he eal wo ld, e en i i is much, much poo e han his one. Bu
om he poin o iew o axonomy, he di e ence is jus a di e ence in g ade. New
ypes o i ual en i ies a e appea ing e e y yea , in p opo ion as ou needs o i ual
ep esen a ion, o communica ion and o s o ing in o ma ion a e g owing, on he one
hand, and on he o he hand he p og amming capaci y o compu e s expands. Bu how
a e asso ed and classi ied all hese di e en ypes o en i ies? The sea ch engines, o
example, o e s a p e-es ablished scheme o sea ching: he Yahoo sea ch engine, o
example, o e s a p e-es ablished classi ica ion o ou sea ches a e ca s, inances,
games, g oups, maps, jobs, spo s, images, news, and so on. I I w i e my name in
he sea ch box and I hi he sea ch bu on o images, I will p obably ind images o
mysel o pho og aphs made by me and displayed on he In e ne . I I w i e my name
and I hi he sea ch bu on o news, mos likely I won’ ind any en ies because I
don’ emembe doing some hing as impo an as o be displayed in he Yahoo news

On ology S udies 8, 2008 158
ca ego y! And again, i I w i e my name and I hi he sea ch bu on o g oups, mos
likely I will ind he discussions g oups o which I subsc ibed. These p e-es ablished
ca ego ies channels he sea ch in a ce ain di ec ion. Tha ’s why i ’s e y impo an o
know p ecisely in which ca ego y alls wha a e we looking o because, as he In e ne
ans a e saying, you can ind any hing on he web as long as you know whe e and how
o sea ch. Bu a e hese ca ego ies a i icially o mula ed o de ined? In o he wo ds, a e
he i ual axonomies which con igu es he In e ne con en ionally made, ollowing
ou epis emic and p ac ical in e es s? I hink he answe is in he same ime yes and no.
I ’s clea enough ha hese ca ego ies a e de ined in such a way as o espond o ou
needs, which is o acili a e ou sea ching on he web: i you a e in e es ed by images,
i ’s much mo e easie o sea ch in a ca ego y which con ains only images. Because he
In e ne was c ea ed, as I said ea lie , o ce ain pu poses. I is a use -cen e ed wo ld,
mo e p ecisely a wo ld cen e ed on he use ’s in e es s, goals, and pe spec i es. Fo
example, one o he main unc ions o he In e ne is ha o o e ing a e y as and easy
o use way o sea ching in o ma ion. Tha ’s why all he sea ch engines a e compe ing
wi h each o he ying o o e mo e analy ical and mo e lexible axonomies e e y
yea , o acili a e ou sea ches. And his is a e y a ough compe i ion! Now, gi en his
goal o sea ching a e ele an in o ma ion, and gi en he di e si y o he in o ma ion
which could be o in e es o he use s, i is easonable (which means na u al) o ha e
a sepa a e ca ego y o news and a sepa a e ca ego y o ca s o ma imonials, al hough
he ad e isemen s o selling ca s could be also conside ed in a way, news. I would
be un easonable (which means unna u al) o ind ma imonials in he news ca ego y!
Fu he mo e, he i ual axonomies a e e ol ing oge he wi h he i ual wo ld which
hey o ganize. When he use s’ in e es s a e ge ing mo e and mo e sophis ica ed,
c ossing axonomies a e appea ing, you can sea ch o news wi h o wi hou images,
you can sea ch o ma imonials wi h o wi hou images (wi hou images would be, o
cou se, unwise!) and so on. All hese axonomies, which e ol es acco ding o he use s’
in e es s, a e ying o be as na u al as hey could be. Bu in which sense do we use he
wo d na u al he e? This ques ion could a ouse, o cou se, e y deep suspicions and
esis ances and could make us o aise ou eyeb ow in dis us because i seems e y
odd o speak o some hing na u al in he i ual wo ld o he In e ne . Bu i we eph ase
he ques ion he suspicions could diminish. We could ask, o example he ollowing:
is i na u al o dis inguish, in he ca ego ies displayed by a sea ch engine, be ween
news and ma imonials? I hink he answe is yes. Because he in o ma ion which we
could ind in he news ca ego y a e o a di e en na u e han he in o ma ion which we
could ind in he ma imonials ca ego y. So we can conside ha hese wo ca ego ies
a e making wo sepa a e na u al kinds. O cou se, i ual na u al kinds. Now we can
ask who decides his o , mo e p ecisely, which is he c i e ion acco ding o which we
es ablish he bo de be ween hese wo ca ego ies o , as I da ed o bap ize hem, hese
On ology S udies 8, 2008 159
wo i ual na u al kinds? I hink he answe is clea enough: he c i e ion is gi en
by he in e es s o he use s. These in e es s a e, o cou se, subjec i e, hey luc ua e,
hey change and a y in ime bu hey gi e bi h o some na u al classi ica ions which
luc ua e acco dingly. I is clea ha hese i ual na u al kinds a e no na u al kinds in
any ealis ic sense. Because he in e es s o he use s canno be conside ed p ope ly
eal essences which could gi e bi h o some na u al kinds as an old- ashioned ealis
would wan . The i ual classi ica ions a e s ongly a ached o he in e es s o he use s.
I hese in e es s a e changing, so a e he i ual classi ica ions, he ca ego ies o he
i ual wo ld o he In e ne . The e is no hing s able once and o all he e, his is why
I said ha he in e es s o he use s a e no eal essences and acco dingly he i ual
axonomies which y o sa is y hese in e es s a e no i ual na u al kinds in he way a
ealis would wan hem o be. None heless, his is no some hing o be wo ied abou .
As I said a he beginning o his alk, as long as we no longe ha e oo many easons o
belie e ha we will be able a some poin o ind such eal essences no e en in he eal
wo ld, we ha e less easons o belie e his when we alk abou a i ual wo ld as he
In e ne . Bu despi e all hese, in his i ual wo ld we s ill need o dis inguish be ween
na u al and a i icial. And we do his by o mula ing i ual na u al kinds. They a en’
na u al in he sense ha hey a e no a ec ed by human in e en ion because hey a e in
ac cons uc ed by us. Bu his aspec is i ele an now. In a wo ld a i icially c ea ed,
which means a wo ld wi hou eal essences, he e is no use in alking abou some hing
una ec ed by human in e en ion.
Wi h his conclusion in mind, le ’s go back o wha we call he eal wo ld. In con as
wi h he i ual wo ld o he In e ne , he eal wo ld is no cons uc ed acco ding o ou
in e es s o he in e es s o he use . Al hough his pe spec i e was indeed main ained
imes and o en, I hink i is oo sel ish o be endo sed. Now, i we keep his analogy
wi h he In e ne , we mus say ha in he eal wo ld, in con as wi h he i ual wo ld in
which we en e ed ecen ly wi h he ad ance o compu e s echnology, he e isn’ jus one
ype o use , bu many ypes. The In e ne is used only by humans, bu he eal wo ld is
used, so o speak, by many o he ypes o use s. I by use s we unde s and li ing beings,
which in e ac s wi h he en i onmen a ound hem, and which ollow hei own goals
and pu poses, hen we can say ha he eal wo ld comp ises a big a ie y o use s. The e
a e humans, o cou se, bu he e a e elines, bi ds, ish, insec s and so on. And all hese
use s ha e hei own speci ic in e es s. We don’ ha e oo many easons o belie e ha in
his en anglemen o speci ic in e es s and ypes o use s, he in e es s o a single ype o
use a e p e ailing, namely he human ype. So we canno p e end ha ou axonomies
a e he eal ones. Bu nei he could we elax wi h he conclusion ha we can o mula e
wha e e axonomies we wan o se e o he bes o ou p esen in e es s and belie e
ha hey a e he eal ones. Because, as I said, in he eal wo ld he e isn’ only one ype
o use and one se o in e es s, as in he case o he In e ne . F om his poin o iew,
On ology S udies 8, 2008 160
he In e ne is a simple and wonde ul wo ld: i is a i ual ne wo k in which humans a e
in e ac ing wi h one ano he and ollow hei own goals and pu poses, indi idually o
collec i ely. Bu hose who in e ac a e only humans. Thei in e es s a e en e ing, b oadly,
in he same ca ego ies, so he i ual axonomies a e ela i ely easy o cons uc . As I said
ea lie , on he In e ne i is na u al o dis inguish be ween ma imonials and news. We
don’ ha e o bo he much wi h sub le de ails and ques ions. Bu in he eal wo ld, we
in e ac wi h many o he ypes o use s which ha e hei own speci ic in e es s. And which
see he wo ld h ough speci ic lenses acco ding o hei in e es s. E en i he axonomies
which hey use o seeing he wo ld a ound hem a e no cons uc ed consciously o
e lec i ely as ou s, hey s ill see he wo ld h ough he lenses o hei own classi ica ions.
And hei axonomies o classi ica ions a e changing in ime also, as ou s. P obably, o he
p ehis o ical elines he i s humans we e a dange ous kind, which should be a oided as a
h ea . Bu in ime, a e he humans domes ica e hem, he si ua ion has changed. Ou ca s
a e no longe a oiding us, bu on he con a y. Today we s a ed o ealize ha in he eal
wo ld he e a e many di e en ca ego ies o use s, which ha e hei own speci ic in e es s
and which see he wo ld acco ding o hese in e es s. Bu o a long pe iod o ime we
igno ed his aspec . We made ou own classi ica ions, we di ided he wo ld in na u al kinds
acco ding o ou own in e es s and we also ound some jus i ica ions o ac ing his sel ish.
The humans a e he only knowing subjec , we used o say and we a e s ill saying, he only
being gi ed by God wi h he igh o ule he wo ld, e c. Bu he esul o his a i ude
was ca as ophic. And his is in no way a su p ise. I we see he animals which inhabi s he
na u al wo ld a ound us as being pa only o such ca ego ies as “p eda o s”, “ea able” o
“unea able”, “ha mless”, and so on, i ’s ob ious ha in a long pe iod o ime we will play
a decisi e ole in he ex inc ion o nume ous species o animals o we’ll de e mine majo
pe u ba ions o he na u al equilib ium. This is jus ano he example o how impo an
a e he axonomies which we cons uc , no only o he way we see he wo ld a ound us,
bu also o he way we come o ac in i .
So, we could say ha o a long ime we cons uc ed he axonomies o he eal wo ld
as we cons uc now he axonomies o he In e ne , which is mainly acco ding o ou
in e es s. In he case o i ual axonomies, which a e shaping he i ual wo ld o he
In e ne his is some hing na u al, use ul and e icien . We a e he only use s and he i ual
na u al kinds in which we di ide his i ual wo ld a e answe ing e y well o ou needs and
in e es s o communica ion. Bu in he eal wo ld his s a egy is no as good o , a leas ,
gi es bi h o many di icul ies. We canno igno e he ac ha in he eal wo ld we a e no
he only use s! So, in his case, wha can we do?
Well, o he s a , maybe i would be wise o pu aside he sea ch o a de ini ion o
he na u al kinds in he s onge ealis ic sense, and y o do wi h jus a de ini ion o wha
could be called he human na u al kinds. Then we could s a o pay mo e a en ion o he
na u al kinds in which di ide he wo ld he o he li ing beings a ound us, he o he use s
On ology S udies 8, 2008 161
which inhabi his ne wo k which we used o call “ he eal wo ld”. And, inally, maybe
i would be wise o sea ch he in e sec ions o hese di e en axonomies. Because i is
possible ha hese in e sec ions could gi e us he in a ian de ini ion which we sea ch and
need o he e m “na u al”. In o he wo ds, hese h ee s eps b ie ly ske ched he e could
be comp essed o a single one huge leap: o abandon he sea ch o eal essences o good,
bo h in he philosophical ealm, whe e we done ha di ec ly o so many cen u ies, and
in he ealm o na u al science, whe e we sea ch o he ul ima e b icks o he Uni e se
which is, I hink, jus a disguised name o he old philosophical sea ch o eal essences.
And a he o sea ch a e he common denomina o s, he in e sec ions o he axonomies
used by he use s which inhabi he eal wo ld.
A e all, as Pla o would p obably ell us, eal essences canno be ind in his wo ld,
in he ca e. Bu despi e his wa ning, we s ill li e in his wo ld and we need o di ide i in
na u al kinds o classes o hings o be able o manage and each ou goals and pu poses,
o o be able o su i e as a species, as Da win would pu i . In many ways, his wo ld is
a di e en wo ld ha he i ual wo ld o he In e ne , his new ca e ha we cons uc ed
ou sel es, a ca e whe e, as I said, he e is only one single ype o kind o use . As long as
he ca s, o example, doesn’ na iga e on he In e ne , we can be assu ed ha he In e ne
is popula ed indeed by hose i ual na u al kinds ha a e answe ing he bes o ou needs
and in e es s and ha hese kinds a e well es ablished. In o he ways, he eal wo ld is no
so di e en om he i ual one. Because, e en i in he eal wo ld he e a e many ypes
o kinds o use s, all hese use s a e di iding he wo ld a ound hem, consciously o jus
ins inc i ely, in classes and na u al kinds acco ding o hei in e es s. And hese in e es s
canno be classi ied acco ding o a unique scale. We canno gi e hem di e en alues
acco ding o an ideal classi ica ion in which human in e es s a e a he op. We canno
belie e anymo e in a wo ld o ideas which could gi e us he model o classi ying he
hings a ound us. And in his espec we ha e o say Pla o a ewell.
Re e ences
Bilg ami, Akeel (2002): ‘Realism and Rela i ism’, Philosophical Issues,12, 1-25
Boyd, Richa d (1991): `Realism, An i-Founda ionalism and he En husiasm o Na u al
Kinds’, Philosophical S udies, 61, 127-148
Da idson, Donald (1974): ‘On he e y idea o a concep ual scheme’, P oceedings and
Add esses o he Ame ican Philosophical Associa ion 47, 5–20
Elde , C aw o d (2005): ‘Unde cu ing he Idea o Ca ing Reali y’, The Sou he n Jou nal o
Philosophy, Vol. XLIII, 41-59
Elde , C aw o d (2004): Real na u es and amilia objec s. Camb idge, Mass.: M.I.T. P ess/
B ad o d Books.