The Definition Of Human Knowledge

Research Essay

— Theaetetus: What Exactly Is The Definition Of Human Knowledge? —

Sandy Ghobrial


PHI 2181: Human Knowledge

Instructor: Dr. Feist

March 23rd & Time


Written circa 369 BC, Theaetetus is one of the notable dialogues of Plato, which concerns the nature of knowledge. In the dialogue, Theaetetus and Socrates were discussing the three core definitions of knowledge. They perceived knowledge as simply a perception, knowledge as a true judgment and knowledge as true judgment coupled with an account. Apparently, in the context of Theaetetus, all of these three definitions are considered unsatisfactory. Since that is the case with the dialogue, Socrates concludes that Theaetetus would have benefited immensely from the discovery of what he did not know and that he could have been better equipped in analyzing the topic in future if his knowledge had been on a higher level (Plato 5). In this paper, I will be analyzing this dialogue, the three main definitions of knowledge it puts out and why this dialogue is essential in human life.

How the dialogue came about

The dialogue was framed by a scene whereby Euclides was telling his friend Terpsion that he had a record of a dialogue between Theaetetus and Socrates, which took place at a time when Theaetetus was a very quiet man. The dialogue is then read out to the two by a slave boy (Plato 6).

During the dialogue, Socrates asks Theodorus if he knows about any geometry students who showed exceptional promise in their studies. Theodorus replied that he did but he just did not want to over-praise the student lest anyone suspected that he was in love with him. The boy was called Theaetetus. He was a young Socrates look-alike. The two elderly men spotted Theaetetus rubbing himself with oil and that is the time when Theodorus reviewed the facts he had stated about him. He said that he was an intelligent orphan whose inheritance at that time had been squandered by malicious trustees (Plato 8).

Once Theaetetus was introduced to Socrates, Socrates told him that he was finding it hard to determine what knowledge was and thus he was looking for a simple formula that could define its exact form. Theaetetus replied that he did not have any idea how he could answer that. From that reply of Theaetetus, Socrates came up with this type of knowledge midwifery and articulated the three definitions of knowledge (Hayek 521). The following sections feature these three definitions.

Knowledge as nothing but a perception Comment by Sandy Ghobrial: What does that mean ?

Socrates is of the opinion that the ideology that knowledge is nothing but a perception ought to be rather identical in meaning. Once Socrates made his proposal, Protagoras followed suit with the idea that man acts as the measure of all things. What that essentially meant is that things are to a person just as they appear to them. Socrates then added that there cannot be any stable objects that can exist with stable enduring qualities (Hayek 523).

These exchanges during the conversation struck one commentator as being disingenuous. Plato already knew that Theaetetus’ opinion regarding knowledge want not the same as that of Protagoras. It is however possible to notice counter-examples of this entailment and the idea that knowledge is just but a perception (Hayek 524).

For instance, there is the idea that knowledge constitutes awareness. On the other hand, there are those who argue that to know is to be able to perceive the things of God. Again, the ideal observer is able to perceive things differently and therefore people fail to perceive or know things insofar as their opinions are the contrary of what God or the ideal observer thinks (McDowell and Brown 54).

The conclusion of whether or not knowledge is simply a perception rests in the human understanding of the idea of knowledge itself. According to Socrates and Protagoras, it is easy to conclude that there are different ways of terming out knowledge but it should not be logically obligatory for people to follow through one definition of what knowledge is or could be (McDowell and Brown 56).

Once Socrates had summed up what he had agreed upon with Theaetetus so far, it became problematic to continue to view knowledge as a sense of perception. That is why he argues that nothing in itself is simply one thing and everything is always in a process of coming into being. Therefore, since there is no exact meaning in things, it is good to appreciate that the Protagorean doctrine does not have a complete answer regarding what knowledge truly is (McDowell and Brown 60).

Knowledge as a true judgment

The push to know more about knowledge is not an aspect that is new to Socrates. For a very long time, he was into philosophy and wanted to unravel great things that others had not. Socrates attempts to try to understand the true definition of knowledge and that is why he asks many questions throughout this dialogue with Theaetetus. However, there is really no reason to suppose that Socrates could have analyzed the nature of knowledge as a perception (Popper 84).

The dialogue between Theaetetus and Socrates is all about the enquiry of what knowledge is. This discussion is then interrupted by two digressions. The first digression is about midwives who provide the platform for a leading thought or image about the subject in question. The other digression in this context is the famous idea of the philosopher and lawyer. In the conversation between the two, this digression provides a landing or a break in the middle of the conversation (Popper 84).

Since Socrates wants to put forth the idea that knowledge is a true judgment, a major part of the Theaetetus dialogue is largely devoted to the idea of setting up definitions of knowledge and science. In every stage of the dialogue, opinion, perception, and reasoning are effectively examined in order to get rid of any confusion that might surround the idea of knowledge and what kinds of knowledge are present to humans (Popper 87).

Even before deciding that knowledge is a true judgment, Socrates agrees that it is not possible to effectively define knowledge until that time that the nature of the definition has been ascertained. That is why he concludes that knowledge is a sensible perception and supports the idea with the assertion that man is a measure of all things. There are different definitions of knowledge that exist in the world even today but the view from Socrates side is that knowledge is a true judgment or opinion (Shulman 7).

However, even if knowledge is true judgement, how can false judgement be deemed to be knowledge? There are major difficulties that come into the conversation in this regard. It is either someone knows or they do not know something. This is because the process of learning and forgetting needs not to be present at all times in humans to be considered viable (Shulman 7).

That being the case, in having a judgement or in thinking, it is important for people to either know or to not know that which they are thinking about. Moreover, people can never know and still be ignorant all at the same time. Essentially, it is not possible to confuse one thing that you do not know with another one that you know. Neither is it possible to for someone to perceive something that they do not know as something that they know (Shulman 9).

Socrates argues that thinking is a conversation that takes place between the mind and oneself. It is a sort of a conversation that is carried out in a question and answer format. This sort of dialogue needs to take place in the mind until that person no longer doubts what they are thinking about. False opinion in this regard comes in arguing that one thing is the other and vice versa. Even if someone tells themselves that good is evil, that will only remain to be a perception but everyone is entitled to their own judgment (Shulman 9).

The confusion that comes up in understanding the true nature of knowledge is necessitated by man’s attempt to explain what false opinion is. It is good to start by explaining what knowledge really is. Theaetetus in this regard agrees with Socrates that knowledge is true opinion or judgement. However, this ideology might not go down well with judges and orators. This is because the orator is notable to convey proper knowledge of a crime whereby the judge was not present. What he can only do in this regard is to persuade the judge to take his position. Depending on the circumstances at hand, the judge may make a true judgment and judge in a truthful manner. However, if true opinion was really knowledge, it would not have been possible for them to judge effectively without any knowledge (Shulman 9).

Towards the end of the dialogue, Theaetetus puts forth another definition that had been running in his mind. He said that knowledge is a true judgment that is accompanied by explanation or definition. At this juncture, it is evident that Theaetetus is largely inclined towards this definition of knowledge. He retreats when Socrates asks him to draw a distinction between the whole and the parts. This becomes quite a challenge for Theaetetus who is an educated student who is being challenged about the nature of knowledge and its true definition (Shulman 11).

In the end, Socrates tells Theaetetus that knowledge is neither a judgement nor a definition that accompanies that same judgement. That is why he tells Theaetetus that little children of his brain are not worth rearing. Socrates challenges Theaetetus to get out of labour and bring out all the ideas he might have about knowledge to birth. Of course, this was a take-home assignment for Theaetetus considering that Socrates told him that the next day he wanted to see him again (Shulman 11).

Knowledge as a true judgment with an account

Theaetetus had already heard that knowledge is a true judgement that is accompanied by logos or an account. This simply meant that only something that has an account can be shown or proven. During the conversation and seeing that Theaetetus does not have more proof to that account, Socrates decides to help him out (Nonaka 25).

Socrates argues that according to the dream theory, the world is made up of complexes together with their accompanying elements. Complexes have accounts whereas elements do not have them. What Socrates meant in this case is that elements could not be known or accounted for. However, they are perceptible. On the other hand, complexes are easily known since people can believe them and go on to give an account of them (Nonaka 27).

In this discussion, the main issue is that Theaetetus and Socrates are talking with each other with a view of determining what someone needs to have in order for them to be deemed as having a good amount of knowledge. As the dialogue opens up, the two agree that knowledge can never be identical or confused as mere belief. That means that, correct judgment is not sufficient for knowledge and thus it might not necessarily be a perfect fit. Theaetetus then argues about a theory he knew about that true judgment coupled with an account constitutes sufficient knowledge. What followed in the dialogue is a discussion about the relevance of the theory in terms of determining what knowledge truly is (Cornford 30).

In getting to figure out the true meaning of knowledge in this context, Socrates argues that giving an account of language is always necessary. What Socrates meant is that giving an account of a judgement or belief is just being able to determine what one thinks about that said judgement or belief. Socrates however says that this alone cannot be a proper description of what knowledge is. He argues that since everyone can give an account in their own making, it is possible that every judgement can constitute knowledge but might not necessarily be correct (Cornford 31).

The second meaning of account is that someone can give an account about something if they have a proper understanding about it. This can be done by reference to the individual parts that make up that something. Therefore, as Socrates argues, one cannot be able to say that they know about wagons if they do not know about the different parts that make up the wagon or how it works. This understanding is quite problematic to many people and Socrates contends that if someone cannot give an account of the different parts that make up a whole, they can never argue that they know anything regarding that subject. Again, knowledge is about giving accounts about the things that are being referred to (Cornford 31).

Last but not least, Theaetetus and Socrates agree that the ability to have an account of something also constitutes being able to effectively identify the properties that make that thing distinguishable from the rest. Socrates in his usual critical self argues that this is a possibility that can also be problematic. If someone makes a judgment about another, it seems as though they have already accounted for that person’s uniqueness. However, it makes no sense if that judgment simply revolves around the person in context. In that case therefore, having an account of somebody cannot just mean coming up with another judgment regarding how different that person is. This is because the first judgment would already have played that role. In light of this discussion, it becomes apparent to both Socrates and Theaetetus that knowledge could probably be a true judgment with an account even though more research and discussions have come up since that time (Cornford 33).


From the analysis of the three definitions of knowledge in this context, it is clear that the dialogue between Theaetetus and Socrates was not at all conclusive. There are still many questions that linger. In any case, what amount of an account would be deemed satisfactory in order for knowledge to be considered worthwhile? From his assertions, it is like Socrates wants people to draw general morals from this dialogue. However, everyone has the freedom to determine their own meaning of knowledge and how that knowledge impacts their lives. Even today, there is a major problem in people trying to understand knowledge and how it impacts people’s lives.

Works Cited

Plato. Theaetetus. Ed. Bernard Williams. Trans. M.J. Levett and (revised) Myles Burnyeat. Indianapolis: Hackett, 1992. Print.

Cornford, Francis M. Plato’s Theory of Knowledge: The Theaetetus and the Sophist. City: Courier Corporation, 2003. Print. Comment by Sandy Ghobrial:

Hayek, Friedrich August. “The Use of Knowledge in Society.” The American Economic Review (2005): 519-530. Print.

McDowell, John, and Lesley Brown. Theaetetus. City: Oxford University Press, 2014. Print. Comment by Sandy Ghobrial:

Nonaka, Ikujiro. The Knowledge-Creating Company. City: Harvard Business Review Press, 2008. Print.

Popper, Karl Raimund. “Objective knowledge: An evolutionary approach.” JOURNAL NAME AND THE VOLUME (2002): 81-106. Print. Comment by Sandy Ghobrial:

Shulman, Lee S. “Those Who Understand: Knowledge Growth in Teaching.”Educational Researcher 15.2 (2006): 4-14. Print.