(c.100 - c.160) An early Christian who demonstrated that the mysteries of Gnosis that were being attacked by some people were actually the deeper truths of Christianity. In the physical world, only fragments of his writings and teachings survive.
"Valentinus [Valentine] was a great master of love and formed a school called the Valentinians. They were dedicated to the study of esoteric Christianity in all its aspects." - Samael Aun Weor, Love
"As to his biography, we know next to nothing. Valentinus was an Egyptian, educated at Alexandria in all that Egypt and Greece had to teach him. The mysterious lore of ancient Khem, the "mathēsis" of Pythagoras, the wisdom of Plato, all helped to fashion his character. But the greatest inspiration of all he found in the last outpouring from the same source from which the wisdom of every true philosopher comes--the stream of Christianity that was swirling along at full tide. But what kind of Christianity did Valentinus encounter at Alexandria? There was no Catechetical School when he was a boy. Pantænus and Clement were not as yet. There were the Logoi, the Sayings of the Lord, and many contradictory traditions; a Pauline community also, doubtless founded by some missionary from Asia Minor; and numerous legends of the mysterious Gnosis which Jesus had secretly taught to those who could comprehend. But, above all things, at the back were the inner schools and communities of the wisdom-traditions and the Gnosis. [...] BEHIND the whole Valentinian movement stands the commanding and mysterious figure of Valentinus himself, universally acknowledged to have been the greatest of the Gnostics. His learning and eloquence are admitted, even by his bitterest opponents, to have been of a most extraordinary nature, and no word has ever been breathed against his moral character. And yet, when we come to analyze the chaos of "information" which Patristic writers have left us on the subject of so-called Valentinianism, we find the mysterious character of the great master of the Gnosis ever receding before our respectful curiosity; he who has been made to give his name to the remodelling of the whole structure, still remains the "great unknown" of Gnosticism. We know nothing certain of him as a man, nothing definite of him as a writer, except the few mutilated scraps which hæresiological polemics have vouchsafed to us." - G.R.S. Mead, Fragments of a Faith Forgotten 
“Gnosis is lived upon facts, withers away in abstractions, and is difficult to find even in the noblest of thoughts.”