Protagoras

Protagoras (c. 490-c. 420 BCE) of the polis Abdera, in the northern region of Greece known as Thrace, was a professional teacher of wisdom. He would travel from city to city and, for a fee, would teach about civic virtue (i.e., how to be a good citizen and human).(3) He was a sophist (meaning), wise man. Sophists didn't argue to the point for coming to truth, but to the point for the coming of the "appearance of wisdom".

Relativism - Protagoras' relativism is based on one of his most famous statements: "Man is the measure of all things: of the things that are, that they are, of the things that are not, that they are not." By this, Protagoras meant that each individual is the measure of how things are perceived by that individual. Therefore, things are, or are not, true according to how the individual perceives them.

For example, Person X may believe that the weather is cold, whereas Person Y may believe that the weather is hot. According to the philosophy of Protagoras, there is no absolute evaluation of the nature of a temperature because the evaluation will be relative to who is perceiving it. Therefore, to Person X, the weather is cold, whereas to Person Y, the weather is hot. This philosophy implies that there are no absolute "truths". The truth, according to Protagoras, is relative, and differs according to each individual.As with many fragments of the pre-Socratic philosophers, this phrase has been passed down through the ages, without any context, and consequently, its meaning is open to interpretation. His use of the word χρήματα (chrēmata, "things used") instead of the general word ὄντα (onta, "entities") signifies, however, that Protagoras was referring to things that are used by, or in some way, related to, humans, such as properties, social entities, ideas, feelings, judgments, which originate in the human mind. Protagoras did not suggest that humans must be the measure of the motion of the stars, the growing of plants, or the activity of volcanoes. (1) 

If we were to take a critical examine of Protagora's ideas, we would think the world can be separated into 1) relative judgments and 2) absolute judgments. The true extent of diversity of these I can not write out here, but will lend two propositional examples: 1) I like chocolate covered cherries. This is a relative taste, as liking indicates preference or sensual judgment. 2) There are stars in the universe. Is by default an absolute judgment or an deductive conclusion.

In this same nature of things in psychology we take on roles that are relational, beingness that is relative to our relations as well relative to our chremata. How we |use| life and how one's life is used by others is in a relational and relative manner. That being an assertion that something that is, or appears for a single individual, is true or real for that individual. So, it may be true you are a daughter to your mother, but not true that you are daughter to some one else's mother. The function of your life is relative, and we see this reverberated in later existential thought.

Knowledge as Perception - Taking Protagoras strictly by his words in the maxim, in the light of this theorem ‘knowledge is perception,’ Socrates attacks the theorem with the view to showing how false this maxim could be by mere appealing to facts of experience. “If we have not learned a foreign language for instance, do we know it by merely hearing it spoken or seeing the script”? (Burrell, 1932:196) Socrates asked. If that be the case, we must deny that we hear the words or see the writing, which we do not understand. If we have learnt it, then we know its meaning, that is, what we cannot see or hear. Invariably, we can infer that knowledge and perception are therefore, not identical in learning a language.

The hypothesis therefore is: “I know what I see” and “I see what I know”. But there is the case of “I do not know what I see” and “I see what I do not know”. Socrates further argued.  (2)

With this in mind, we can relate this back to relativism. "I know x" but "She doesn't know x." This exhibits that what is known is relative to the observer.

“If we have not learned a foreign language for instance, do we know it by merely hearing it spoken or seeing the script”? (Burrell, 1932:196) Socrates asked. If that be the case, we must deny that we hear the words or see the writing, which we do not understand. If we have learnt it, then we know its meaning, that is, what we cannot see or hear. Invariably, we can infer that knowledge and perception are therefore, not identical in learning a language. (2) What that factor is can only be hinted at by this unknowing mind. It might be later discovered in other publications. It seems as though this analogy signifies the idea that meaning is learned.

Can Vice and Virtue be Taught? Early Virtue Ethics:

"Not only is this true of the state, but of individuals [as well]; the best and wisest of our citizens are unable to impart their political wisdom to others: as for example, Perikles, the father of these young men, who gave them excellent instruction in all that could be learned from masters, in his own [area] of politics neither taught them, nor gave them teachers; but they were allowed to wander at their own free will in a sort of hope that they would [discover] virtue [on their own]."

Many of find ourselves learning to do things by our own power to learn, while other things like mathematics might have needed years of instruction to know and use accordingly.

Later on in the Protagoras, "He who desires to inflict rational punishment does not retaliate for a past wrong which cannot be undone; he has regard to the future, and [desires] that the man who is punished, and he who sees him punished, may be deterred from doing wrong again." (3)

This relays a modern psychological method for behavior modification, Operant conditioning. Wherein we learn from being punished what is wrong, and learn from being rewarded what is right. This is the teachers natural endowment, instruction.

So, if we to specify a virtue (cleanliness) we could think of how to reward that behavior and its required tasks, and in doing so have accomplished instruction in (a physical) virtue. Likewise, vice may be taught, embedded in one's personality structure. How? Either by not punishing vice or by rewarding vice. Each of us stray between these in the outplay of the development of personal conscience/pathology. As far as Behaviorism holds, this is an adequate philosophy for teaching and civil discipline.

This is how justice (Rational Discipline) was defined : "in a word, [human] virtue—if this is the quality of which all men must be partakers, and which is the very condition of their learning or doing anything else, and if he who is [lacking] in this, whether he be a child only or a grown-up man or woman, must be taught and punished, until by punishment he becomes better, and he who rebels against instruction and punishment is either exiled or condemned to death under the idea that he is incurable—if what I am saying [is] true, good men have their sons taught other things and not this, consider how they think virtue [can be] taught and cultivated both in private and public." (3)

To relate the text back to itself, "Is Virtue and Vice Relative or Absolute"? Even if it were either one, it wouldn't matter, because the essence of virtue and vice, of good and evil, can be KNOWN and TAUGHT. Conclusively, that it what should be taken from such philosophical dialect.

Works by Protagoras :

https://www.google.com/search?q=works+by+protagoras&rlz=1C1CHBF_enUS877US877&oq=works+by+protagoras&aqs=chrome..69i57.5030j1j9&sourceid=chrome&ie=UTF-8

References:

1. https://en.wikipedia.org/wiki/Protagoras#Relativism
2. https://pdfs.semanticscholar.org/429b/268ef5e13ba1b503c8fdce7a753549d8a0d8.pdf
3. https://www.mesacc.edu/~barsp59601/text/105/notes/read/historical/protagoras.pdf