Plutón, Venus, Frege y los misterios del lenguaje natural

Pablo de Lora
Universidad Autónoma de Madrid
 
Los lenguajes naturales (el que estoy empleando en este momento) adolecen de algunas patologías bien conocidas, aunque no por ello menos desconcertantes cuando se inspeccionan con los anteojos del filósofo.

Tal vez la más célebre sea la vaguedad de los conceptos. Si bien no todos los lógicos estarían de acuerdo, parece natural decir que algo es o no es algo y tertium non datur (esta es la denominada «ley del tercio excluso», una de las leyes más importantes de la lógica de predicados clásica). Los griegos, sin embargo, pronto advirtieron que las cosas no eran tan simples. Es al lógico megárico Eubúlides de Mileto a quien se atribuye el célebre «razonamiento de Sorites», un razonamiento que nos hace concluir que no existen cosas tales como «montones de arena» («sorites» quiere decir montón en griego) o, alternativamente, que un grano de arena constituye un montón de arena, o que, en algunos casos algo no es ni blanco ni negro sino indeterminado (el vulgar «gris» con el que apuntalar nuestra híbrida toma de posición en las discusiones cotidianas). Eubúlides nos pregunta si billones de granos forman un montón de arena, ante lo cual nuestra respuesta será obviamente que sí. Ese mismo montón lo seguirá siendo aunque sustraigamos uno de los granos, y si proseguimos así, granito a granito, llegará un momento en el que un solo grano seguirá siendo un montón (pruebe el lector a proceder a la inversa para concluir que no existen cosas tales como montones de arena). Lo que el razonamiento o paradoja de Sorites muestra es que no es nunca sencillo determinar con nitidez el punto a partir del cual un objeto se convierte en otra cosa, dónde empieza la línea de la gordura, calvicie, altura, etc. En general, los conceptos de los lenguajes naturales son vagos cuando no somos capaces de listar con precisión absoluta todas las condiciones que algo debe reunir para engrosar la denotación del concepto.

En los últimos tiempos, los astrónomos se las han tenido que ver con la engorrosa vaguedad de los lenguajes naturales (ellos tan acostumbrados a la exactitud del lenguaje formalizado por excelencia, la matemática) cuando de definir lo que es un planeta se ha tratado. El resultado, como saben, ha consistido – y permítaseme la ironía- en expulsar a Plutón del planetario. Y ello no sin arduas discusiones semánticas más propias de juristas, seres afanados en determinar con exactitud (¡oh! ilusos) términos tales como «alevosía», que de científicos naturales. Para más inri, la controversia se ha saldado finalmente mediante votación. Algunos malévolos habrán pensado: «curioso método científico éste». En realidad, que Plutón sea o no un planeta no es un asunto científico, sino puramente nominal. ¡Qué más da cómo le cataloguemos! Los nombres comunes son convenciones lingüísticas, y los problemas de vaguedad se resuelven, como no, acudiendo a una precisión dada en un lenguaje no vago como el matemático. Si por definición decimos que un montón de arena debe tener un número X (siendo X un número entre 0 e infinito) de granos, o un objeto tales y cuales dimensiones para ser un planeta, se acabó el problema. La precisión será convencional también, pero nos salva la vida, o, al menos, nos evita estériles discusiones verbales.

Otro ilustre déficit de los lenguajes naturales que les quiero presentar es la ambigüedad, el fenómeno consistente en que un mismo término cuenta con distintos significados («banco», «puro»). En esos casos, es el contexto donde el término aparece el que nos aclarará su significado. ¿Y el fenómeno inverso? ¿Existen términos o proposiciones distintas con el mismo significado? La respuesta es obviamente sí, si pensamos en Venus, un planeta (de momento) al que durante muchos siglos los seres humanos se han referido con dos expresiones diferentes «la estrella matutina» y «la estrella vespertina» pues creían que de dos objetos distintos se trataba. Desde tiempo ha sabemos que son la misma, así que podemos concluir que:

(1)Venus=estrella matutina
(2)Venus=estrella vespertina

Estos enunciados de identidad supusieron un buen quebradero de cabeza para quien pasa por ser el padre de la lógica matemática contemporánea: Gottlob Frege. La razón es, de nuevo, simple y su solución también conocida y harto discutida. De acuerdo con una vieja distinción debida a Kant, las proposiciones (tales como «Venus es la estrella matutina») pueden ser analíticas o sintéticas. La verdad de las primeras es «definicional», se basa en los significados de los términos empleados. Así, para comprobar que «solterón es el varón no casado», no tengo que desarrollar labor empírica alguna, cosa que sí me es exigida en cambio cuando me las veo con una proposición «sintética» tal como «Venus no contiene agua en su superficie». De las dos oraciones anteriores (1) y (2) yo puedo fácilmente concluir (3) Venus=Venus y (4) la estrella matutina= la estrella vespertina. Esas oraciones son equivalentes, pero su carácter no es el mismo. (3) es una proposición analítica, pero (4) no lo es. (3) no me informa de nada y (4) sí. Esta es la razón por la cual Frege (y después Russell), haciéndose eco de una larga tradición que se remonta a Platón, concluye que los nombres propios como «Venus» o «Shakespeare» sólo denotan (carecen de intensión o connotación), pues en otro caso nos veríamos obligados a admitir que existen enunciados de identidad («Venus es Venus» o «Shakespeare es Shakespeare») de naturaleza contingente (y parece que «Venus es Venus» es una verdad necesaria) o proposiciones sintéticas tales como «Venus es la estrella matutina» o «Shakespeare es el autor de Hamlet» de naturaleza necesaria (y parece que en ambos casos tales proposiciones son verdaderas a posteriori, el fruto de la investigación en el mundo).

En «Über Sinn und Bedeutung» («Sobre el sentido y la referencia», su célebre artículo de 1892) Frege nos ha legado además otra forma de concebir las relaciones de identidad que tanto a lógicos como a matemáticos conduce por las calles de la amargura. De acuerdo con el lógico alemán, expresiones tales como «estrella vespertina=estrella matutina» o «2×2=8-4» tienen la misma referencia («Venus», «4») pero distinto significado. ¿Cómo es ello posible? Porque en estos casos hemos de considerar que el mismo objeto (la referencia de las expresiones o su denotación) es presentado de modos diversos. A ese «presentar» a los objetos de distinto modo Frege lo llama «sentido» (Sinn). Corolario: los términos (de los lenguajes naturales o artificiales) expresan su sentido y denotan su referencia y ambas cosas (sentido y referencia) conjuntamente conforman su significado.

Frege fue el máximo inspirador de una corriente filosófica que no ha hecho gran fortuna: el logicisimo. Junto con otros célebres matemáticos (como David Hilbert) anhelaba poder reducir toda la matemática a unos cuantos axiomas lógicos. Para muchos filósofos de otras disciplinas, el espíritu fregeano ha permeado en la forma de un cierto estilo a la hora de afrontar los problemas filosóficos, una actitud que tiene que ver con la inquisición acerca del sentido en el que las palabras son empleadas en el discurso filosófico o vulgar. Muchos pensamos que en numerosas ocasiones la tarea filosófica prioritaria – y para algunas única- es desvelar esos «modos de ser presentados los objetos o ideas», analizar el lenguaje natural con el que nos referimos al mundo y a nosotros mismos, pues la experiencia nos revela que, como en el caso de Venus, no pocos puzzles metafísicos son sólo aparentes; no pocas de las dificultades anunciadas a bombo y platillo no son tales sino «pseudoproblemas» y no pocos de los misterios filosóficos son tan sólo el resultado de haber llenado con hojarasca semántica el patio de nuestros pensamientos. 

Compartir:

812 comentarios

  1. Generally my attention drifts on long posts but this one held it through the end, and a stop at ideasflowstrategically earned the same sustained focus, content that defeats my drift tendency is content with substantive pulling power and this site has demonstrated that pulling power across multiple pieces in a session that has now run quite long actually.

  2. A piece that took its time without dragging, and a look at directionpowersmovement kept the same patient pace, the difference between unhurried and slow is a fine editorial distinction and this site has clearly found the unhurried side without slipping into the slow side which would have lost me as a reader quickly otherwise.

  3. Found this really helpful, the explanations are simple but they actually answer the questions a normal reader would have, and after I followed strategyengine I had a clearer sense of the topic, no extra fluff just useful points laid out in a sensible order that made the time worth it.

  4. Thanks for keeping things clear and to the point, that is honestly hard to find online these days, and after reading through progressmovesforwardnow the message stayed consistent which makes me trust the information being shared more than I usually do on similar pages that cover this same kind of topic.

  5. The post made the topic feel approachable without making it feel trivial, that is a fine balance, and a stop at progressmovesintelligently maintained the same balance, finding the middle ground between welcoming and serious is genuinely difficult and the writers here have clearly figured out how to consistently hit it well across many different posts.

  6. Skipped the comments to avoid spoilers and came back later to find them genuinely worth reading, and a stop at ideamomentum extended that surprised respect, when the discussion below a post matches the quality of the post itself you have found something special and this site appears to attract that kind of audience.

  7. Reading this on the train into work was a better use of the commute than my usual choices, and a stop at growthfocusednetwork extended that commute reading well, content that improves transit time rather than just filling it is content with practical benefit and this site has earned its place in my morning commute reading rotation.

  8. This one is staying open in a tab for the rest of the day so I can come back and re read certain parts, and a look at focuspowersdirection suggests I will be doing the same with a few more pages here too, this is going to be a deep dive over the coming hours.

  9. Just sat back at the end of the post and felt grateful that someone took the time to write it, and a look at growthacceleration extended that gratitude across more of the site, recognising effort behind quality work is part of what makes the open web a community rather than just a marketplace today.

  10. Closed three other tabs to focus on this one and never opened them again, and a stop at smartgrowthbond similarly held attention exclusively, content that crowds out other reading from working memory is content with real density and this site has demonstrated that density across multiple pages I have visited so far this morning.

  11. Just sat with this for a bit longer than I usually would because the points are worth thinking about, and after growthactivator I had even more to chew on, the kind of post that nudges your thinking forward without forcing the issue is something I have always appreciated in good writing online.

  12. Honest reaction is that this is the kind of writing I would defend in a conversation about good blog content, and a look at signalguidesgrowth reinforced that, the rare site whose work I would actively recommend rather than just tolerate is the kind I want to support through return visits regularly.

  13. Closed the laptop after this and let the ideas settle for a few hours, and a stop at mutualgrowthnetwork similarly rewarded reflective time, content that benefits from sitting with rather than racing past is the kind I want more of and the kind that this site appears to consistently produce week after week here.

  14. Bookmark folder created specifically for this site, and a look at nextgenalliancelink confirmed the dedicated folder was the right call, dedicated folders for individual sites are a level of organisation I rarely deploy and this site has earned that level of dedicated tracking based on the consistency I have seen so far across sessions.

  15. Quietly impressive in a way that does not announce itself, and a stop at strategyvector extended that quiet impressiveness, the kind of quality that emerges through sustained attention rather than first impressions is the kind I trust more deeply and this site has been earning that deeper trust across multiple sessions over time consistently.

  16. Reading carefully here has reminded me what reading carefully feels like, and a look at directioncreatesimpact extended that reminder, the experience of careful reading versus skimming is different in ways I had partially forgotten and this site has clearly refreshed my memory of what attention feels like when content rewards it consistently.

  17. Definitely returning here, that is decided, and a look at signalcreatesdirection only made the case stronger, this is one of those rare websites that rewards regular visits rather than feeling stale after the first read which is something I cannot say about most of the places I bookmark today across all my topics.

  18. Felt slightly impressed without being able to point to one specific reason, and a look at growthadvancescleanly continued that diffuse positive feeling, when content works at a level you cannot easily articulate the writer is doing something with craft rather than just delivering information and that is something I have learned to recognise.

  19. Recommended without hesitation if you care about careful coverage of this topic, and a stop at claritybuilder reinforced the recommendation, the bar I set for unhesitating recommendations is fairly high and this site has cleared it through the cumulative weight of multiple consistently good pieces rather than through any single standout post which is meaningful.

  20. A genuine compliment to the writer for keeping the post focused on what mattered, and a look at anchortrustbond continued that disciplined focus, focus is a editorial choice that compounds across many small decisions and this site has clearly made those small decisions consistently across what I have read so far this week here.

  21. Liked the careful selection of which details to include and which to skip, and a stop at trustedalliedbond reflected the same editorial judgement, knowing what to leave out is just as important as knowing what to include and this site has clearly figured out where that line sits for the topics it covers regularly.

  22. Worth pointing out the careful word choice in this post, no buzzwords and no jargon, and a look at strategyalignment continued that disciplined vocabulary, sites that resist the pull of trendy language are sites that will read well in five years and this one is clearly built for that kind of long durability.

  23. Quality work here, the post reads cleanly and the points stay focused throughout, and a stop at visioninmotion kept the standard high, you can tell the writer cares about the final result rather than just hitting publish for the sake of having something new on the page to feed the search engines.

  24. Reading this on a phone at a coffee shop and finding it perfectly suited to that context, and a stop at focusroute continued the comfortable mobile experience, content that works across reading conditions without compromising on substance is increasingly important and this site has clearly thought about the whole reader experience here.

  25. Took my time with this rather than rushing because the writing rewards attention, and after claritytrajectory I had even more to absorb, the kind of content that pays back the patient reader rather than punishing them with empty filler is something I look for and rarely find in regular searches lately.

  26. Thanks for the simple approach, too many sites bury the actual point under layers of unnecessary words, but here every line earns its place, and a look at focusbuildsclarity showed the same care for the reader which is something I will remember the next time I need answers on a topic.

  27. Felt this in a way I cannot quite explain, the topic just hit different here, and a stop at actionmovescleanly continued in that vein, sometimes you find a site whose perspective lines up with how you have been thinking and reading their work feels like a small relief which I appreciated more than I expected.

  28. During a quiet evening reading session this provided just the right depth without being heavy, and a stop at progressinitiator maintained the same evening appropriate weight, content with depth that does not exhaust the reader is content with editorial calibration and this site has clearly figured out how to be substantial without being demanding all the time.

  29. If I had to summarise the editorial sensibility of this site in a few words it would be careful and human, and a look at synergygrowthalliance extended that summary feeling, capturing the essence of a sites approach in brief is hard but this site has a clear enough identity that the summary comes naturally enough.

  30. The conclusions felt earned rather than tacked on at the end like an afterthought, and a look at clarityspark kept that careful structure going, you can tell when a writer has thought about the shape of their post versus just letting it ramble out and hoping for the best at the end which most do.

  31. Thanks for a post that does not try to be funny when it is not the moment for it, and a stop at directionfuelsprogress maintained the same appropriate seriousness, knowing when humour helps and when it just signals desperation for engagement is a sign of editorial maturity that many blogs have not developed yet.

  32. Closed the tab with a small sense of finality rather than the usual rushed exit, and a stop at elitebusinessbond produced the same considered closing, when reading ends with deliberate satisfaction rather than impatient skip you know the time was well spent and this site is producing those satisfying endings consistently across what I read.

  33. A slim post with substantial content per word, and a look at growthflowswithpurpose maintained the same density, the content per word ratio is something I track informally and this site scores high on that ratio compared to most sources I read regularly which is a quiet indicator of careful editorial work behind the scenes.

  34. Reading carefully this time rather than scanning, and the depth shows up in places I missed first time around, and a look at globalpartnershipnet rewarded the same careful approach, content that holds up to multiple reads is content I want more of in my regular rotation rather than disposable scroll fodder daily.

  35. Really appreciate that the writer did not overstate the importance of the topic to make the post feel weightier, and a quick visit to clarityguidesgrowth maintained the same modest framing, content that is honest about its own scope rather than inflating itself is the kind I trust and return to repeatedly over time.

  36. Just wanted to say this was useful and leave a small note of thanks, and a quick visit to heritagetrustbond earned a similar nod from me, the small acknowledgements add up over time and represent the real economy of trust that good content runs on across the open and increasingly fragmented modern internet.

  37. A handful of memorable phrases from this one I will probably use later, and a look at progressignition added a couple more, content that contributes language to my own communication rather than just facts is content with a different kind of utility and this site is providing that linguistic utility consistently across what I read.

  38. A piece that was confident enough to leave some questions open rather than forcing closure, and a look at ideapipeline continued that intellectual honesty, content that admits the limits of its scope is more trustworthy than content that pretends to total understanding and this site has the right calibration on certainty consistently.

  39. Reading this in pieces over a coffee break and finding it consistently rewarding, and a stop at directionanchorsprogress extended that into related material I will return to later, the kind of site that fits naturally into small reading windows without requiring a long uninterrupted block is genuinely useful for how I actually browse.

  40. Reading this confirmed a hunch I had been carrying about the topic without having articulated it, and a stop at unifiedcapitalgroup extended the confirmation, content that gives shape to fuzzy intuitions is doing the rare work of making private thoughts public and this site is providing that articulating service consistently for me lately.

  41. Recommend this to anyone who values clear thinking over flashy presentation, and a stop at focusbuildsenergy continued in the same understated way, this site has its priorities in the right place which makes it worth supporting through repeat visits and recommendations rather than just one passing read today before moving on quickly elsewhere.

  42. Came away feeling slightly smarter than I was when I started, that is a real win, and a stop at clarityfocus added a bit more to that, the rare site that actually transfers some of its knowledge to the reader in a way that sticks rather than just creating an illusion of learning briefly.

  43. Got pulled in by the headline and stayed because the content actually delivered on the promise, and a stop at forwardpathenergized kept that trust intact, when a site lives up to its own framing it earns the right to keep showing up in my browser tabs going forward indefinitely from here on out really.

  44. Once you find a site like this the search for similar voices begins, and a look at trustedpartnershipnet extended the search energy, finding a high quality reference point makes the gap between it and adjacent sources visible in a way it was not before and this site has provided that high reference point across multiple recent visits.

  45. Reading more of the archives is now on my plan for the weekend, and a stop at claritypowerschoices confirmed the archive worth the time, the rare archive worth a dedicated reading session rather than just casual sampling is the rare archive of serious work and this site has clearly produced enough of that work to warrant the deeper exploration.

  46. I really like how the writer keeps the tone friendly without sounding fake or overly polished, and after a stop at clarityguidesdecisions the same calm pace was there, no rushing to make a point and no padding either, just clean honest writing that I can respect and come back to later again.

  47. Thank you for being clear and direct, that simple approach saves so much frustration on the reader’s end, and a stop at ideafocus only made me more sure of it, the rest of the content seems to follow the same pattern which is a great sign of consistent editorial care behind the scenes.

  48. Reading this confirmed a hunch I had been carrying about the topic without having articulated it, and a stop at thinkactflow extended the confirmation, content that gives shape to fuzzy intuitions is doing the rare work of making private thoughts public and this site is providing that articulating service consistently for me lately.

  49. Worth every minute of the time spent reading, and a stop at growthsignalpath extends that value across more pages, in a media environment where most content is engineered to waste attention this site stands out by treating reader time as something valuable rather than something to be exploited and stretched as far as possible.

  50. Probably the best thing I have read on this topic in the past month, and a stop at directionenergizesgrowth extended that ranking, the casual ranking of recent reading is informal but real and this site has been winning those rankings for me on this topic specifically over the last several weeks of regular reading sessions.

Deja un comentario