Discussion Question 4

Read: Plato, Theaetetus, Selection of fragments from Heraclitus

This dialogue is very difficult and meanders through multiple issues. Accordingly, the discussion question for this week is mostly targeted at trying to figure out what is going on in one part of the text.

At 151d, Theaetetus defines knowledge to be perception, and Socrates follows up by introducing Protagoras’ theory that man is the measure of all things at 152a. How would you characterize Protagoras’ claim in your own words? Socrates also connects Theaetetus’ definition to a Heraclitean picture of the world at 152d. How would you characterize this corresponding metaphysical view? (try to get each down to a sentence or two – a very hard task, but a useful one to practice.)

Do you think these related views are required to make sense of Theaetetus’ definition? If so, why? If not, why not?

9 thoughts on “Discussion Question 4

  1. Heraclitean : This view of knowledge feels much more Christian than Greek, as in god is everywhere and he binds all living things together. While, he does state “Logos” instead of god, he however, speaks of Logos in the same manner you would aspect a modern day catholic to speak of god. It is essentially Chisitian-Greek if you will.

    Protagoras: He’s saying that, because man has shaped the world according to his perception of it, then his views have more or less become the marking point for each object’s shaped. In a sort of way, as we defined a triangle to be a triangle because of how we decided to characterize it.

    Yes and No; I believe that Protagoras’s views may be required, as Protagoras is defining man who is himself a formed by his perception of the world and everything, and uses it to define those things. However, Heractile says in one line, essentially that dumb people think they’re smart.

  2. To say that “man is the measure of everything is” is the almost narcissistic way of saying that our personal perspective, in this case, man’s, is the only possible way to measure something, since it is the only perspective we are able to see. The metaphysical view Socrates introduces in 152d is closely linked to this, arguing that an object that we know as “large” may appear to another, say an elephant, as small. Therefore successfully explaining that knowledge is in the eye of the beholder.

    Though these related views are not a requirement in understanding Theaetetus’s definition of knowledge, they are useful examples made to further the comprehension of students reading the discussion. To completely understand a concept we have to be able to experience it first hand, and in this way, the student has a better grasp on such an elusive concept.

  3. Within this section, Protagoras’s theory that “man is the measure of all things”, places great import on the experiences and perceptions of an individual, even given situations in which we believe now to be ‘subjective’. This appears to be very closely linked with the solipsist philosophy—which is that each and every individual exists alone in the world, and all that can be ‘known’ to exist is the existence of one’s self. Different experiences create perception, thus ‘knowledge’, as can be observed within the example of two men feeling the wind. While it is arguably the same wind, the two men experience different things (perception of temperature, strength, etc.) It’s through this example that we can observe that the wind’s existence has been verified through these two perceptions—differing perceptions do not contradict existence; it simply provides contextual evidence.

    On the other hand, Heraclitus seems to believe the contrary—that there is already a predestined truth/existence within the world, and man is not capable/unable to look at the the whole picture without initial bias, simply because man is too caught up within himself to properly observe his surroundings. His belief is that things are ever-changing, constantly in development, and from the definition of an object.

    Protagoras’ definition of perception as knowledge is based on a system of relativity—for example, one type of food may be spicy to one, while mild to another. Heraclitus argues something different—things are constantly changing, so perception cannot be said to equate to knowledge, as perception and knowledge must be separate in the face of the ‘truth’ of the world.

  4. Socrates’ interpretation of Protagoras’ claim seems to be that man is a culmination of all things. We see this in the example he provides, when he says that two people can experience wind and have different perceptions of its temperature. These conflicting accounts do not negate the existence of wind, but are rather different perceptions that establish the existence. Both accounts in a way add to the understanding of the wind. Man is then necessarily the larger understanding of all these experiences, not the individual experience, because that would be an incomplete understanding. This means that how something is “measured” through perception can vary by the individual, and for this reason the real truth is the addition of these perceptions.

    It seems that Heraclites says that there is an ultimate understanding that rules the universe, but it avoids human understanding. This is because individuals are caught up in their own bubble that is guided by their personal perceptions and interactions with the world, thus they miss the “big picture”. Along these lines, Socrates establishes that nothing ever “is”, only becoming, which means to say that our understanding of what is is actually misleading because we are missing that “”big picture.

    In this way, I think these views negate Theaetetus’ definition that knowledge is perception. The perception he speaks of is not the complete knowledge of what is/isn’t, but rather a fraction of the understanding that may guide to what is the ultimate. This seems related to when Heraclites establishes that to gather information is not to increase understanding/insight.

  5. It is difficult to get these down to a sentence or two, but here it goes!

    Theaetetus claims that knowledge is perception and that one cannot know something that is non-perceivable. Protagoras’s theory is that nothing “is” as it is, but rather exists by what it is becoming. Socrates associates existence by movement and change and that the state of rest means that whatever is being perceived is no longer perceivable aka doesn’t exist. When saying that “man is the measure of all things” is to associate our changing perception of the very physical world around us through education, knowledge, experience (aka movement) is to bring life to this reality. By measuring ourselves in relation to the perceivable world around us is to bring existence to that world and by man being measured in relation to the world is also to bring existence to man. I hope this makes sense!

    These views are definitely useful when relating back to Theaetetus’s theory because man cannot be measured and changed without the perception of this change aka knowledge. An example would be that knowledge of atoms didn’t exist until man measured himself against the concept of small and discovered something new to be perceived and now we have gained knowledge to all living things around us by measuring how large or small they are in relation and the movement and changing of these atoms in turn creates life.

  6. If I am reading correctly, Socrates asks back, “that as each thing appears to me, so it is for me, and as it appears it you, so it is for you— you and I each being a man?” In trying to understand Theaetetus when he explains Protagoras. One thing could have it’s meaning to an individual while another to another, the existence doesn’t change of a thing – just the perspective from man to man. With things in constant flux doesn’t that mean there will be a new perspecption on something therefor nothing is permanent in opinion? To say that man is the measure of all things is to put the responsibility and all value on the man’s vision of something (I.E Is the sky blue? But man saying it isn’t – automatically the sky isn’t blue).

    Socrates breaks it down into a more into “but this expression ‘it appears’ means ‘he perceives it’?” Nothing in itself is just one thing, saying that you shouldn’t basically judge a book on it’s cover or a crumb when it’s a bolder. It’ll appear in the light as itself.

    Naturally, like stated by Socrates, we tend to call things by what they “are” it’s automatic from our experiences if we know of it. But can we say the same for things we know nothing about? Can the perception be more common for the unknown?

  7. I believe that Protagoras’ claim that ‘man is the measure of all things…’ (152a) is meant to describe the relative perspectives of different individuals on things both material and abstract. For example, to one person an object might appear to be large, but to another it might seem to be small. This property of size is not intrinsic to the object, but has everything to do with the observer. It is impossible then to ascribe absolute attributes to anything.

    The Heraclitan view is a bit different in that it describes things as being in constant flux. The changing nature of things prevents them from being described as they ‘are’ since the process of change is continuous. This dynamic property is characteristic of an object, so it both ‘is’ and ‘is not’ simultaneously.

    I think both views enrich Theaetetus’ statement that ‘… a man who knows something perceives what he knows, and the way it appears at present, at any rate, is that knowledge is simply perception’ (151d). Protagoras’ view confirms the idea that perception forms a basis of what man takes to be knowledge (whether this is truly knowledge or not is of course debatable), and I agree that our sense perceptions do indeed supply us with much of what we know about the world. But the Heraclitan idea points out a problem with Theaetetus’ claim: that it is not really possible to conclusively infer knowledge from perception, since the objects of our perception are not fixed but ever-changing, as are our perspectives. Thus some acceptance of relativism seems necessary in order to move forward with our search for a working definition of knowledge.

  8. By the encouragement of Socrates, Theaetetus devised his first opinion towards knowledge as knowledge is perception. According to the theory that “ man is the measure of everything”, the perception could be considered as a very reliable representation of knowledge, indicating people’s direct belief towards something no matter they know or do not know. What’s more, as people become a certain measure, their understanding of one object could be varied from one to one. Everyone’s perception seems to be unique and irreplaceable. In 152d, Socrates then emphasized that no one could be, simply depending on its own existence as everything is changing, in a state of going to be something. For a metaphysical explanation, an athlete A is participating an jumping competition. Before his first jump, he is sitting by side and eating a chocolate bar. The image in our mind is a stable person which is known as the perception 1 of A. During the process of jumping, he achieves the highest point, and the instance we perceive is the perception 2 of A. A’s outer appearance seems to be always identical in a relatively short time, but his motion changes as time changes, even energy consumed also changes in his body as it cannot be directly perceived. It demonstrates that the rule that everything is changing.

    Personally, I believe that these theories could not well present the definition of knowledge-perception. To begin with, perception itself is relatively ephemeral, and it requires two objects, one is known as our mind, which turns daily-life things into the image, and the other as the perceived could build a certain relationship under certain conditions. It must depend on the cooperation of movement of two objects, producing a new movement called perception. If any factors which cause the movement change, the final product presented in our mind could never be identical to the initial one. Plato pointed out that this definition has something in common with Protagora’s “man is the measure of all things” as a result of people being centralized in relation to things. So there is such a saying that “I feel the wind is cold, so the wind is cold.” , which reflects the personal and subjective impression. However, Socrates’ concern is quite deeper, and he casts doubt on the continuity of perceptual content and the identity among different perceptors. Therefore, the objects in perception lack continuity and identity. The reality of “perception” can only be supported by my current experience. However, one’s current experience can only indicate the current nature of perception, but it cannot guarantee that it will still support future perception. Therefore, the object of perception cannot be perceived. Forming a continuous experience of perception cannot form the logical form required by perception.

  9. Protagoras’s theory that “man is the measure of all things” places ultimate supremacy in the individual experience and its subjective perceptions. It seems that, according to Protagoras, an object’s ontic state is determined by how or if it is perceived. Protagoras’s theory recalls to my mind a David Foster Wallace line from a review of John Updike’s Toward the End Time: “When a solipsist dies… everything goes with him.” (I am aware that this quote is derived from an Anthony Burgess line, but Wallace’s quote is a bit more acutely relevant.) Put simply, Protagoras believes that perception is a preconception of existence, and without being perceived, an objective world ceases to exist.
    Heraclitus’s metaphysical theory, on the other hand, explains that no object exists in a definite state; everything is constantly changing, becoming. To Heraclitus, life is an endless renewal. Heraclitus once expounded his theory through analogy: explaining that, for example, the same river could not be stepped in twice.
    Theaetetus’s metaphysical theory is definitely inextricable from Protagoras’s (which seems to be a crude ontogenetic precursor). That being said, I don’t think that the influence of Heraclitus’s theory of Universal Flux is in any way visibly present or in evidence in Theaetetus theory of epistemology as a question of perception; the two are simply two disparate for Heraclitus to have positively influenced Theaetetus’s definition — though some form of negative influence is entirely plausible.

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