The starting point with studying the Renaissance is just learning what the word means: rebirth. But what was being reborn? The answer is the culture and ideas of classical Europe, ancient Greece and Rome. Renaissance thinkers and artists very consciously made the claim that they were reviving long-lost traditions from the classical world in areas as diverse as scholarship, poetry, architecture, and sculpture. The feeling among most Renaissance thinkers and artists was that the ancient Greeks and Romans had achieved truly incredible things, things that had not been, and possibly could never be, surpassed. Much of the Renaissance began as an attempt to mimic or copy Greek and Roman art and scholarship (corresponding to one another in classical Latin, for example), but over the decades the more outstanding Renaissance thinkers struck out on new paths of their own - still inspired by the classics, but seeking to be creators in their own right as well.
Of the various themes of Renaissance thought, perhaps the most important was humanism, an ancient intellectual paradigm that emphasized both the beauty and the centrality of humankind in the universe. Humanists held that humankind was inherently rational, beautiful, and noble, rather than debased, wicked, or weak. They sought to celebrate the beauty of the human body in their art, of the human mind and human achievements in their scholarship, and of human society in the elegance of their architectural design. Humanism was, among other things, an optimistic attitude toward artistic and intellectual possibility that cited the achievements of the ancient world as proof that humankind was the crowning achievement of God’s creation.
Renaissance humanism was the root of some very modern notions of individuality, along with some specific phenomena such as the idea that education ought to arrive at a well-rounded individual. The goal of education in the Renaissance was to to realize as much of the human potential as possible with a robust education in diverse disciplines. This was a true, meaningful change over medieval forms of learning in that education’s major purpose was no longer believed to be the clarification of religious questions or better intellectual support for religious orthodoxy; the point of education was to create a more competent and well-rounded person instead.
Along with the idea of a well-rounded individual, Renaissance thinkers championed the idea of Civic Humanism: one’s moral and ethical standing was tied to devotion to one’s city. This was a Greek and Roman concept that the great Renaissance thinker Petrarch championed in particular. Here, the Medici of Florence are the ultimate example: there was a tremendous effort on the part of the rich and powerful to invest in the city in the form of building projects and art. This was tied to the prestige of the family, of course, but it was also a heartfelt dedication to one’s home, analogous to the present-day concept of patriotism.
Practically speaking, there was a shift in the practical business of education from medieval scholasticism, which focused on law, medicine, and theology, to disciplines related to business and politics. Renaissance learning was born in the cities of northern Italy because of the wealth of northern Italy. Princes and other elites wanted skilled bureaucrats to staff their merchant empires; they needed literate men with a knowledge of law and mathematics, even if they themselves were not merchants. City governments began educating children (girls and boys alike, at least in certain cities like Florence) directly, along with the role played by private tutors. These schools and tutors emphasized practical education: rhetoric, math, and history. Thus, one of the major effects of the Italian Renaissance was that this new form of education, usually referred to as "humanistic education" spread from Italy to the rest of Europe by the late fifteenth century. By the sixteenth century, a broad cross-section of European elites, including nobles, merchants, and priests, were educated in the humanistic tradition.
A “Renaissance man” (note that there were important female thinkers as well, but the term "Renaissance man" was used exclusively for men) was a man who cultivated classical virtues, which were not quite the same as Christian ones: understanding, benevolence, compassion, fortitude, judgment, eloquence, and honor, among others. Drawing from the work of thinkers like Socrates, Plato, Aristotle, Cicero, and Virgil, Renaissance thinkers came to support the idea of a virtuous life that was not the same thing as a specifically Christian virtuous life. And, importantly, it was possible to become a good person simply through studying the classics – all of the major figures of the Renaissance were Christians, but they insisted that one’s moral status could and should be shaped by emulation of the ancient virtues, combined with Christian piety. While the Renaissance case for the debasement of medieval culture was overstated - medieval intellectual life prospered during the High Middle Ages, there was definitely a distinct kind of intellectual courage and optimism that came out of the return to classical models over medieval ones during the Renaissance.