Pico Della Mirandola: Oration On the Dignity Of Man (1496)
If there is such a thing as a "manifesto" of the Italian Renaissance, Pico della Mirandola's "Oration on the Dignity of Man" is it; no other work more forcefully, eloquently, or thoroughly remaps the human landscape to center all attention on human capacity and the human perspective. Pico himself had a massive intellect and literally studied everything there was to be studied in the university curriculum of the Renaissance; the "Oration" in part is meant to be a preface to a massive compendium of all the intellectual achievements of humanity, a compendium that never appeared because of Pico's early death.
Pico was a "humanist," following a way of thinking that originated as far back as the fourteenth century. Late Medieval and Renaissance humanism was a response to the dry concerns for logic and linguistics that animated the other great late Medieval Christian philosophy, Scholasticism. The Humanists, rather than focussing on what they considered futile questions of logic and semantics, focussed on the relation of the human to the divine, seeing in human beings the summit and purpose of God's creation.
Their concern was to define the human place in God's plan and the relation of the human to the divine; therefore, they centered all their thought on the "human" relation to the divine, and hence called themselves "humanists." At no point do they ignore their religion; humanism is first and foremost a religious movement, not a secular one (what we call "secular humanism" in modern political discourse is a world view that arises in part from "humanism" but is, nevertheless, essentially conceived in opposition to "humanism"). Paul Brians