The Form of the Good is the greatest thing to learn about, and that it is by their relation to it that just things and [other virtuous things] become useful and beneficial. (Republic, 505a) Plato suggests that justice, truth, equality, beauty, and many others ultimately derive from the Form of the Good.
Republic is firstly an argument about the ideal structure of a city. Notoriously, Plato installs philosopher-kings as a benevolent council. If the rulers of the city are to make themselves, their citizens, and their city good, they must first know Goodness itself. 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. Stephen Hawking famously quipped that we should ask not only what the equations governing the universe are, but also “what breathes fire into the equations?” For Plato, both the equations and the fire are the Form of the Good.
Plato’s was the first major metaphysical system in the West, and it dominated Western thought through the middle of the second millennium. Consider the subject of mathematics and geometry. What is a point? It is a location in space with no dimension. In other words, it is not a real object. Points are ideal entities, not space-time particulars. They take up no space. Likewise, lines have length but no breadth. Mathematics is about ideal entities, and some mathematicians today are still “Platonists” about numbers: they hold the view that numbers or other mathematical objects are immaterial things. And they have to be in order for us to be able to know eternal truths about them.
If we live in a rationally ordered cosmos, this helps underwrite a social order that is rigidly hierarchical. It is no surprise then that through the Middle ages humans organize themselves into strict hierarchies. We find a hierarchical church and a stratified social structure, with serfs serving the king and the king serving God.
Consider Plato’s influence on theology: The Form of the Good is the ground of all being, an immaterial object that exists more perfectly than anything else, a thing responsible for the goodness and rationality in the world. This is something like an interpretation of the Christian view of God developed in the Middle Ages, founded in Platonic and Neo-Platonic metaphysics.
Perhaps most importantly, Plato’s arguments in Republic make possible scientific inquiry. Science is only possible if the natural world is intelligible to our rational faculties. Many people credit Plato’s student Aristotle with the initiation of the scientific project of humanity, and many in turn credit the scientific method as the West’s most profound contribution to humanity.
Aristotle along with other scholars sees the Form of the Good as synonymous with the idea of One. Plato claims that Good is the highest Form, and that all objects aspire to be good. Since Plato does not define good things, interpreting Plato’s Form of the Good through the idea of One allows scholars to explain how Plato’s Form of the Good relates to the physical world. According to this philosophy, in order for an object to belong to the Form of the Good, it must be One and have the proper harmony, uniformity, and order to be in its proper form.
Love & truth,
Summa Catechetica, "Neque enim quaero intelligere ut credam, sed credo ut intelligam." – St Anselm, "Let your religion be less of a theory, and more of a love affair." -G.K. Chesterton, "And above all, be on your guard not to want to get anything done by force, because God has given free will to everyone and wants to force no one, but only proposes, invites and counsels." –St. Angela Merici, "I want a laity, not arrogant, not rash in speech, not disputatious, but men and women who know their religion, who enter into it, who know just where they stand, who know what they hold and what they do not, and who know their creed so well that they can give an account of it."- Bl John Henry Newman, Cong. Orat., "We cannot always have access to a spiritual Father for counsel in our actions and in our doubts, but reading will abundantly supply his place by giving us directions to escape the illusions of the devil and of our own self-love, and at the same time to submit to the divine will.” —St. Alphonsus Ligouri, "The harm that comes to souls from the lack of reading holy books makes me shudder . . . What power spiritual reading has to lead to a change of course, and to make even worldly people enter into the way of perfection." –St. Padre Pio, "Screens may grab our attention, but books change our lives!" – Word on Fire, "Reading has made many saints!" -St Josemaría Escrivá, "Do you pray? You speak to the Bridegroom. Do you read? He speaks to you." —St. Jerome, from his Letter 22 to Eustochium, "Encounter, not confrontation; attraction, not promotion; dialogue, not debate." -cf Pope Francis, "God here speaks to souls through…good books“ – St Teresa of Avila, Interior Castle, "You will not see anyone who is really striving after his advancement who is not given to spiritual reading. And as to him who neglects it, the fact will soon be observed by his progress.” -St Athanasius, "To convert someone, go and take them by the hand and guide them." -St Thomas Aquinas, OP. 1 saint ruins ALL the cynicism in Hell & on Earth. “When we pray we talk to God; when we read God talks to us…All spiritual growth comes from reading and reflection.” -St Isidore of Seville, “Also in some meditations today I earnestly asked our Lord to watch over my compositions that they might do me no harm through the enmity or imprudence of any man or my own; that He would have them as His own and employ or not employ them as He should see fit. And this I believe is heard.” -GM Hopkins, SJ, "Only God knows the good that can come about by reading one good Catholic book." — St. John Bosco, "Why don't you try explaining it to them?" – cf St Peter Canisius, SJ, Doctor of the Church, Doctor of the Catechism, "Already I was coming to appreciate that often apologetics consists of offering theological eye glasses of varying prescriptions to an inquirer. Only one prescription will give him clear sight; all the others will give him at best indistinct sight. What you want him to see—some particular truth of the Faith—will remain fuzzy to him until you come across theological eye glasses that precisely compensate for his particular defect of vision." -Karl Keating, "The more perfectly we know God, the more perfectly we love Him." -St Thomas Aquinas, OP, ST, I-II,67,6 ad 3, “But always when I was without a book, my soul would at once become disturbed, and my thoughts wandered." —St. Teresa of Avila, "Let those who think I have said too little and those who think I have said too much, forgive me; and let those who think I have said just enough thank God with me." –St. Augustine, "Without good books and spiritual reading, it will be morally impossible to save our souls." —St. Alphonsus Liguori "Never read books you aren't sure about. . . even supposing that these bad books are very well written from a literary point of view. Let me ask you this: Would you drink something you knew was poisoned just because it was offered to you in a golden cup?" -St. John Bosco " To teach in order to lead others to faith is the task of every preacher and of each believer." —St. Thomas Aquinas, OP. "Prayer purifies us, reading instructs us. Both are good when both are possible. Otherwise, prayer is better than reading." –St. Isidore of Seville “The aid of spiritual books is for you a necessity.… You, who are in the midst of battle, must protect yourself with the buckler of holy thoughts drawn from good books.” -St. John Chrysostom