Dennis Maust
Dennis Maust and Mom

“Truth Changes Depending on the Light” –

How Does Socrates Inform My Personal Aphorism?



“. . . you will deny that such a man knows the good itself, or any other good?  And if he somehow lays hold of some phantom of it, you will say that he does so by opinion and not knowledge, and that, taken in by dreams and slumbering out his present life, before waking up here he goes to Hades and falls finally asleep there?”


Socrates to Glaucon (Book VII, 534c)



“But it isn’t holy to betray what seems to be the truth.”


Socrates to Glaucon (Book X, 607c)



But of course untruth is also the opposite of truth.  For this reason, as the nonessence of truth, it is appropriately excluded from the sphere of the question concerning the pure essence of truth.  This human origin of untruth indeed only serves to confirm by contrast the essence of truth “in itself” as holding sway “beyond” man.  Metaphysics regards such truth as the imperishable and eternal, which can never be founded on the transitoriness and fragility that belong to man’s essence.


Martin Heidegger,

“The Age of the World Picture” (124)



“Or is it the nature of acting to attain to less truth than speaking, even if someone doesn’t think so?”


Socrates to Glaucon (Book V, 473a)



“. . . all made their way through terrible stifling heat to the plain of Lethe.”


Socrates telling the story of Er (Book V, 473a)




The Greeks have the word alētheia for revealing.  The Romans translate this with veritas.  We say ‘truth’ and usually understand it as correctness of representation.


Martin Heidegger,

“The Question Concerning Technology” (318)



“In four days they arrived at a place from which they could see a straight light, like a column, stretched from above through all of heaven and earth, most of all resembling the rainbow but brighter and purer.  They came to it after having moved forward a day’s journey.  And there, at the middle of the light, they saw the extremities of its bonds stretched from heaven; for this light is that which binds heaven, like the undergirders of triremes, thus holding the entire revolution together.”


Socrates to Glaucon,

The Republic of Plato (Book X, 615b)



“Aletheia (Queen of Truth), who art the beginning of great virtue, keep my good-faith from stumbling against rough falsehood.”


Pindar (Fragment 205)



“Mehr licht.”


Goethe's last words (purportedly)



            I extend my apologies for the numerous epigrams above.  However, they serve at least two purposes.  Standing over the body of the work, they comprise its essence.  Contained within the work, they introduce and order the investigation.  (Plato would not need to elaborate so, but I am no Plato.)

            Perhaps four years ago or more, not remembering exactly and not having handy my infrequently used journal, I experienced what I call a waking dream, starring me, of course.  I call it a waking dream because I consciously knew I was dreaming.  Knowing that I could completely wake myself at any moment, I followed the dream.  I remember now none of the circumstances of the dream, except that at a critical juncture, the me in my dream uttered a phrase that the conscious me deemed consequential, important enough to record.  In hindsight, I doubt the thought very original.  However, at the moment those words left my imagined mouth, I immediately ended the dream.  Easily forcing myself awake, I scribbled the phrase onto a torn piece of yellowish-orange scratch paper cluttering my nightstand.  Some time later, I transferred the scribbled phrase more neatly to my journal; the scratch paper entered service as a bookmark.  I committed to memory this seemingly profound phrase.  I had by then inflated it to a self-proclaimed, stratospheric, “profound” category, like I do with many random thoughts and notions when I first become mindful of them, thinking them instructive or useful.  Usually time, or the act of detailing such thoughts in writing, grounds me again to the reality of my banal, mortal self.  Now, all these years later as we work through The Republic of Plato – my first attempt – I wonder what Socrates might think about my dreamy wit.  Specifically, how does Socrates inform my dusty, germinating apothegm:  “Truth changes depending on the light”?

Socrates works through so many questions in The Republic that after his final, dialogue-ending assertion, even though he seems to have answered most of the questions raised from its beginning, dialogue participants may yet feel quite inadequate and, actually, a bit shamed at having not fared well.[1]  No matter.  Readers should heartily accept Plato’s invitation to participate.  However, with trepidation now, I attempt to revisit Plato’s pages, extracting if possible a Socratic judgment on the wisdom of my shaky insight regarding truth.  Breaking it down before reopening the pages of the dialogue raises several questions.  What is truth?  Does Socrates address truth like he does the good, and the idea of the good, or must we presuppose a definition of truth, a common a priori understanding?  If so, what definition?  Probably the central question affecting the validity of my supposed insight is “Can truth change?”  If so, how does Socrates illuminate this dance involving truth and light?  Is the singular word “light” operative and exclusive, or might another word or phrase add depth, improving the understanding and practicality of my home-grown saying?  Does this notion of a relationship between light and truth help inform life?  I suppose, in the end, I would really like to know if I should banish it to the trash bin like so many other previous, random thoughts.

            The opening epigrams, like the questions above, give structure to this search.  The first and last epigrams serve as bookends, bespeaking my fears and hopes.  While dreaming, did I take hold of some phantom?  Did it take hold of me?  Will I end finally asleep in Hades?  I rather hope my truth-pronouncement resulted from sleeping “in such a state [that] most lays hold of the truth” (Book IX, 572a).  I hope I took care that night, and take care each night, before falling asleep to awaken my “calculating part,” feed my “desiring part,” and soothe my “spirited part” (Book IX, 571e).  If, indeed, my apothegm turns out a phantom, a shadow, I hope it may yet prove beneficial.  To that end, the last epigram offers an apt prayer for guidance, balance, and to stay on course in this truthful search.

People largely describe general notions about, or the nature of, truth using words like eternal, unchanging, enduring, and universal.  Truth usually elicits claims to fact, actuality, and even supreme reality.  Unlike Socrates, many people often find such eternal truths in art, poetry, tragedy, and comedy (perhaps especially comedy).  Yet Socrates puts forth several arguments that would essentially banish artists and poets from his just city – for teaching untruths.  The work of artists and poets, for Socrates, culminates in an “imitating concerned with something that is third from the truth” (Book X, 602c).  He sees this imitating as detrimental to souls and especially harmful to the education of the city’s children.  We might tend to agree today, considering television’s influence and video games’ addictive power, especially though not exclusively regarding children.

The censorship arguments of Socrates seem to support the prevailing notion of truth’s universality and unchangeability, a notion echoed above in the first Heidegger epigram, where metaphysics attributes the origin of untruth to man and the essence of truth to “beyond” man.  Socrates points to a similar holiness-nature of truth in each of his censorship arguments in the founding of his just city.  In Book II, when answering his own question, “Would a god want to lie, either in speech or deed by presenting an illusion?” Socrates claims ultimately that gods alone are entirely truthful.  He describes a “true lie” as a voluntary lie; it is “truly a lie” because of its effect, that is, because of its lingering “ignorance in the soul of the man who has been lied to” (382a - 382c).  Socrates attributes these lies and imitations to parts of poetry and speech that leave an “affection in the soul, a phantom of it that comes into being after it, and not quite an unadulterated lie” (382c).  Apparently, we cannot adequately differentiate poetry’s effect from life’s actuality, although the problem may again apply most acutely to children’s education.  Only “the demonic and the divine are wholly free from lie” (382e).  Indirectly then, at least in Book II, truth adheres to its characteristic eternal, unchanging quality.[2]  Later, using the image of a mirror and a couch in Book X, Socrates repeats his argument for censorship.  Again, he seems to associate a thing’s absolute or first-order truth only with the gods.[3]

            Still, truth – or the “idea of truth,” although not specified as such by Socrates like he speaks of the idea of the good – does not remain constant throughout the dialogue.  So that we do not completely ignore them, however, several instances regarding truth occur throughout The Republic and deserve a very quick glance, if only to increase awareness of how frequently “truth” arises in conversation.  In these instances, Socrates uses the notion of truth only descriptively or categorically, that is, assuming an a priori understanding of truth:  for example, true “tales told about what is in Hades” (330e); a “definition of justice, speaking the truth and giving back what one takes” (331d); divination as “very true” (349a); “truly to persuade” (357b); pursuing “a thing dependent on truth” (362a); “true opinion” (413a); “[t]o speak knowing the truth” (450d); “in slipping from the truth where one least ought to slip” (451a); “the truth about fair, just, and good things” (520c); the truth about his just city, that is, “the truth is surely this:  that city . . . is necessarily governed in the way that is best and freest from faction” (520d); “[the real tyrant] is most in need of the most things and poor in truth” (579e); and “we were telling the truth about [the soul] as it looks at present” (611c).  While most dialogue participants likely understand abstractly the meaning of these notions of truth, this incomplete account of “truth” instances does not substantially assist this current search for concrete definition.

However, a few other instances prove more informative.  They even hint at an unholy and slippery notion of truth, a variable nature, and a nature of truth involving degree or kind.  The epigram above where Socrates speaks to Glaucon regarding the “less[er] truth” of acting vs. speaking gives us a first instance to consider.  This slippery notion of truth arises when Socrates admits that an actual just city will never be as perfect as his ideal just city, the city of mind.  A second instance occurs during an early discussion of telling tales (those poor poets!) to children.  Socrates emphasizes that “surely [the tales] are, as a whole, false, though there are true things in them too” (Book II, 377a).  We can quite agree that tales comprise a mixture of false and true parts.  As fully myths or stories, they are false in the whole, yet they serve useful purposes in the education of children – hence we divine a certain notion about finding degrees or levels of truth in art and, in this case, storytelling.

Another instance of the possibility of truth existing in a less than whole state – that is, as true but not entirely true – occurs when Socrates begins his third proof of the “victory” of the just man over the unjust man.  Here, he observes that truth may not be entirely pure.[4]  Generalizing from these, in a sense more significantly definitional, instances of truth, Socrates appears to encourage a bit of doubt about its nature.  Seemingly then, while gods may lay claim to eternal, unchanging truth in speech and action, man can comprehend truth.  He can even, with effort, create it in his mind and speak of it.  However, man cannot realize or actualize eternal, unchanging truth in his earthly world.  (Do we not “actualize” when we speak?)

Heidegger offers help here with the Greek.[5]  With the mention of the “plain of Lethe” (621a) and the “river of Lethe” (621c) in the story of Er in Book X, Socrates subtly commits us to an examination of the Greek word for truth (alētheia).  Bloom notes that Lēthē means “forgetfulness,” the negation of which gives alētheia, the Greek word translated in Bloom’s Republic as “truth” (Book X, Footnote 19).  Adding the notion of “oblivion”[6] to our overall understanding of Lēthē, then alētheia, as the approximate opposite and negation of “forgetfulness” and “oblivion,” takes on an expansive sense of remembrance, awareness, consciousness, understanding, and even perhaps knowledge, intelligence, and wisdom.  In fact, Socrates makes us keenly aware of a very close relationship between truth and wisdom,[7] as well as a dependence of truth upon intelligence.[8]  I here take intelligence to mean nearly, if not actually, the same thing as knowledge, because Socrates later confirms Glaucon’s exposition that thought lies between opinion and intelligence,[9] whereas he alternately opposes opinion to  knowledge (and ignorance).  We must acknowledge that although we certainly think about truth and the truth of things, to call a thing true in the most accurate sense, we necessarily require absolute knowledge of that thing; otherwise, we merely state an opinion.  (I think my conclusion here to be true, but I do not know it to be true; therefore, it is not a truth but merely an opinion.)

Socrates goes into greater detail:

Therefore, say that what provides the truth to the things known and gives the power to the one who knows, is the idea of the good.  And, as the cause of the knowledge and truth, you can understand it to be a thing known; but, as fair as these two are – knowledge and truth – if you believe that it is something different from them and still fairer than they, your belief will be right.  As for knowledge and truth, just as in the other region it is right to hold light and sight sunlike, but to believe them to be sun is not right; so, too, here, to hold these two to be like the good is right, but to believe that either of them is the good is not right.  The condition which characterizes the good must receive still greater honor.  (Book VI, 508e – 509a)


Though I noted Socrates provides more detail, I do not admit that Socrates clears up our messy language.  It seems Socrates provides an almost familial relationship between truth and knowledge.  Perhaps he makes them siblings or cousins, with the good as their mother.  Unfortunately, so much depends on how we perceive the good and the idea of the good that more detail would require a closer examination of the meaning Socrates gives to the good and its idea (at least one more paper).

Returning briefly to Heidegger, he further unpacks the notion of alētheia by offering its supposedly more literal translation as “unconcealment,” or the negation of concealment.[10]  Additional insight comes from noting interplay between Lēthē and alētheia, concealment and disclosure, undisclosedness and “revealing,” the translation Heidegger makes in his second epigram above.  This yin-and-yang notion supposedly points to the essence of truth.[11]  It seems provocatively reminiscent, too, of the interplay between knowledge and ignorance, being and non-being, and what is and what is not, explored by Socrates.

These complex interrelationships involving notions of truth and untruth, when combined with (1) the idea about truth as variable, as ranging in degree or kind, already pulled – or teased – from The Republic, (2) the allegorical notion of truth as “shadow painting” to help differentiate just and unjust men, and (3) the nature of truth as dimming light[12] regarding artisans and producers of couches, move us toward the divided line and the image of the cave as the next logical place to investigate whether “Truth changes depending on the light.”

            From Book VI, we gather that truth is related to measure (sense, sensibleness, sensibility), more akin to wisdom than anything, and that a lover of learning, a philosopher, “must from youth on strive as intensely as possible for every kind of truth” (485c – 486d).  How, though, does this relate to the explanations of Socrates and his images of the sun, the divided line, and the cave?  Simply put, truth, like wisdom and knowledge in relation to the good, appears to be a concept of and in the intelligible realm.

We must eventually access truth to arrive at the good – by going over and going up.  That is, we must go over from the visible-sensible-opinion realm of conjectures, images, belief, and objects to the knowledge-wisdom-truth-intelligible realm of understanding, thought, dialectic, and ideals-forms.  Simultaneously whereby we go up through the opinionable items of the visible realm to arrive at (or see) the sun, we similarly go up through the knowledgeable items of the intelligible world to arrive at (or “see,” in its intellectual, imaginative sense) the good.  Captivatingly, as the items in the visible realm inform us of the sun, the sun also informs us of them.  It changes our notion of conjectures, beliefs, images, and objects depending on the light it sheds.  The sun reveals, or unconceals, these items to us and for us.  Items in the intelligible realm, including truth, relate similarly, and likewise in both directions, to the good.  They inform the good, and the good informs them.  (Whew!  That was a mouthful, so to speak.  No wonder Socrates uses images.)

Now, when one speaks of finding the truth, it must result from this relationship it shares with the good.  Finding the truth, essentially and ultimately, means a revealing or disclosure of the truth by the good.  However, one must be careful.

            In the cave, Socrates relates these divided-line movements – that is, going over and going up – to an unchaining, an unbinding or freeing, a turning away from the shadows on the wall previously in front, and a compelling to look at the light.  This slow, very painful process eventually results in the realization that what one now sees is “truer” than what one previously – and obligatorily – saw.  Here, the cave dweller must be careful.  To stop with only knowledge of the light of the fire, he still gets a truer sense of things, and a truer sense of truth.  But if he turns further and goes up still higher, compelled somehow, he eventually sees the even truer light of the sun.  This light informs him more accurately of his previous conditions – and the conditions of the shadow-makers in the cave.  Compelled still higher, he leaves the limits of the cave.  Not yet able to look fully and with complete awareness at the sun, the former cave dweller senses objects outside the cave via their shadows and reflective images.  Becoming accustomed to the sun’s light, this newly informed, “free” person begins to directly sense new, other-world objects revealed by the sun, while simultaneously also beginning to know the sun.

But should the former cave dweller rest comfortably now, eventually settling into knowledge of all objects revealed completely by the sun and eventually knowing the sun completely?  Does he know the sun completely?  I assume that Socrates used the sun also as an image of constancy, of eternity, and of ever-enduring.  What if Socrates found out the sun changes, grows brighter or dimmer, and even dies?  How would that change his sense of the good, and hence, our sense of truth?  Perhaps he would think that if the sun, the child of the good, does not remain for eternity, unchanged, as the brightest light, there may exist another light, even brighter, and an even higher good.

Returning now to the last book of The Republic, Socrates does give us an even brighter light – and, possibly, a more constant light, though my personal notion here remains unclear.  In his story of Er, Socrates speaks of a light of heaven, of the cosmos, that seems over and above the sun.[13]  How many more “lights” might there be?  How many higher goods might exist?  Have we arrived at the cause of all causes?  Is this the truth of all truths?  Because the story of Er hints at another, even higher degree of knowledge, truth, and understanding, and consequently, a higher, brighter notion of the good, itself revealing more fully the truth, perhaps the cave dweller’s soul might “calculate” the possibility of more levels of truth, of brighter lights informing truth and changing truth, possibly ad infinitum.

This ever-evolving idea of the good, based on an ever-increasing number of “suns” or “lights,” in turn reflects another possible way to understand an evolving truth or changing truths.  Perhaps it goes down a path of apprehending the good unintended by Socrates.  However, Socrates conceivably might intend for us to think about his images and stories in this alternative, possible way.  Even if Socrates believes his sun images portray only one possible sun and a notion of only one eternal, highest good, negating this alternative thought, he still leaves us with truth that both informs and depends on light – light that changes from fire illuminating shadows to sun illuminating a cave, causing shadows and reflections, and eventually revealing itself completely to man.  Consequently, truth still changes as a result of the changing light.

Therefore, I think I will maintain my personal aphorism a while longer.  “Truth changes depending on the light.”  One might argue that position in relation to the light, not merely the light itself, makes a difference.  Hence, one might offer “Truth changes depending on your position,” or “Truth changes depending on where you stand,” or “Truth changes depending on your point of view.”  In the interest of keeping things simple – should not we look for the simplest truth in the case of competing truths? – I will stick with “Truth changes depending on the light.”  I may keep it with me until I fully understand – until I stand on one or the other side of the river Lethe, until I start this crazy notion of life all over again.

Still, how does my apothegm inform this life?  Such is also the subject for another paper, at least one more paper.  Suffice it to say, remembering that “Truth changes depending on the light” provides a constant reminder to practice reflection and the maintenance of an open, receptive mind, and to always consider – in addition to the object or thought at hand – the possibility of a shadow or phantom in my midst.  Always ask, “Am I informing and being informed by the absolute brightest light?”  Then again, how can I ever really know?

            As an apology, perhaps I biased my investigation here with the hope that my dreamy pronouncement always contained a kernel of truth.  Perhaps my life experiences predisposed me to recognize that, at different times and places in my life, I “understood” the truth of things differently.  Or perhaps there exists an idea of truth as eternal and unchanging, while the truth of things and, quite probably, truth itself do change.  I am not sure our language, or at least my language, is adequate to persuade, one way or the other.

            Thank you, Aletheia, for guiding my steps.

Works Cited



Heidegger, Martin.  “The Age of the World Picture.”  The Question Concerning Technology

and Other Essays.  Trans. William Lovitt.  New York:  Harper Torchbooks, 1977.


---.  “On the Essence of Truth.”  Basic Writings.  Ed. David Farrell Krell.  New York: 

HarperCollins, 1993.


---.  “The Question Concerning Technology.”  Basic Writings.  Ed. David Farrell Krell.  New

York:  HarperCollins, 1993.


Pindar.  The Odes of Pindar.  Trans. Sir John Sandys.  Cambridge, MA:  Loeb-Harvard UP,



Plato.  The Republic of Plato.  2nd ed.  Trans. Allan Bloom.  Basic Books, 1991.


[1] Speaking ultimately to Glaucon, Socrates concludes (probably tired and hungry), “And so here and in the thousand year journey that we have described we shall fare well.”  (Book X, 621d)

[2] To Glaucon, Socrates elucidates:  “Then the god is altogether simple and true in deed and speech, and he doesn’t himself change or deceive others by illusions, speeches, or the sending of signs either in waking or dreaming.”  (Book II, 382e)

[3] “There turn out, then to be these three kinds of couches:  one that is in nature, which we would say, I suppose, a god produced. . . .And then one that the carpenter produced. . . . And one that the painter produced” (597b).

[4] “Observe that the other men’s pleasure, except for that of the prudent man, is neither entirely true nor pure but is a sort of shadow painting, as I seem to have heard from some one of the wise” (Book IX, 583b).

[5] I have yet to decide whether to thank or curse one classmate for suggesting this digression into Heidegger.

[6] Preceptorial notes from 10 August 2006.

[7] “Now could you find anything more akin to wisdom than truth?”  (Book VI, 485c)

[8] “Haven’t you noticed that all opinions without knowledge are ugly?  The best of them are blind.  Or do men who opine something true without intelligence seem to you any different from blind men who travel the right road?”  (Book VI, 506c)

[9] “. . . you seem to me to call the habit of geometers and their likes thought and not intelligence, indicating that thought is something between opinion and intelligence.”  (Book VI, 511d)

[10] “Western thinking in its beginning conceived this open region as ta alēthea, the unconcealed.  If we translate alētheia as ‘unconcealment’ rather that ‘truth,’ this translation is not merely more literal; it contains the directive to rethink the ordinary concept of truth in the sense of the correctness of statements and to think it back to that still uncomprehended disclosedness and disclosure of beings.”  (“On the Essence of Truth,” 125)

[11] “Concealment deprives alētheia of disclosure yet does not render it sterēsis (privation); rather, concealment preserves what is most proper to alētheia as its own.  Considered with respect to truth as disclosedness, concealment is then undisclosedness and accordingly the untruth that is most proper to the essence of truth.”  (“Essence,” 130)

[12] “Therefore, let’s not be surprised if this too turns out to be a dim thing compared to the truth” (Book X, 597b)

[13] “In four days they arrived at a place from which they could see a straight light, like a column, stretched from above through all of heaven and earth, most of all resembling the rainbow but brighter and purer.   They came to it after having moved forward a day’s journey.  And there, at the middle of the light, they saw the extremities of its bonds stretched from heaven; for this light is that which binds heaven, like the undergirders of triremes, thus holding the entire revolution together.”  (Book X, 616b-616c)