The Form of the Good

Plato describes "The Form of the Good", or more literally "the idea of the good" (ἡ τοῦ ἀγαθοῦ ἰδέα), in his dialogue the Republic (508e2–3), speaking through the character of Socrates. Plato introduces several forms in his works, but identifies the Form of the Good as the superlative. This form is the one that allows a philosopher-in-training to advance to a philosopher-king. It cannot be clearly seen or explained, but once it is recognized, it is the form that allows one to realize all the other forms.

The first references that are seen in The Republic to the Form of the Good are within the conversation between Glaucon and Socrates (454 c–d). When trying to answer such difficult questions pertaining to the definition of justice, Plato identifies that we should not “introduce every form of difference and sameness in nature” instead we must focus on "the one form of sameness and difference that was relevant to the particular ways of life themselves” which is the form of the Good. This form is the basis for understanding all other forms, it is what allows us to understand everything else. Through the conversation between Socrates and Glaucon (508 a–c), Plato analogizes the form of the Good with the sun as it is what allows us to see things. Here, Plato describes how the sun allows for sight. But he makes a very important distinction, “sun is not sight” but it is “the cause of sight itself.” As the sun is in the visible realm, the form of Good is in the intelligible realm. It is “what gives truth to the things known and the power to know to the knower”. It is not only the “cause of knowledge and truth, it is also an object of knowledge”.

Plato identifies how the form of the Good allows for the cognizance to understand such difficult concepts as justice. He identifies knowledge and truth as important, but through Socrates (508d–e) says, “good is yet more prized”. He then proceeds to explain “although the good is not being” it is “superior to it in rank and power”, it is what “provides for knowledge and truth” (508e).

Plato writes that the Form (or Idea) of the Good is the ultimate object of knowledge, although it is not knowledge itself, and from the Good, things that are just, gain their usefulness and value. Humans are compelled to pursue the good, but no one can hope to do this successfully without philosophical reasoning. According to Plato, true knowledge is conversant, not about those material objects and imperfect intelligences which we meet within our daily interactions with all mankind, but rather it investigates the nature of those purer and more perfect patterns which are the models after which all created beings are formed. Plato supposes these perfect types to exist from all eternity and calls them the Forms or Ideas. As these Forms cannot be perceived by human senses, whatever knowledge we attain of the Forms must be seen through the mind's eye (cf. Parmenides 132a), while ideas derived from the concrete world of flux are ultimately unsatisfactory and uncertain (see the Theaetetus). He maintains that degree of skepticism which denies all permanent authority to the evidence of sense. In essence, Plato suggests that justice, truth, equality, beauty, and many others ultimately derive from the Form of the Good.

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