"I'm sure those qualities are found in every species."
"But not in such confusing abundance."
Human philosophy changed much over its history. It was dramatically altered after Zefram Cochrane's test of his warp drive, which initiated Earth's First Contact with an alien species. Within fifty years, poverty, hunger, and war among the nations of Earth had been abolished. Racism and other prejudices soon followed. The discovery of extraterrestrial life and new philosophies such as the Vulcan concept of IDIC, placed Humanity's self-image in a new perspective. (TOS: "Let That Be Your Last Battlefield"; Star Trek: First Contact)
The philosophy of many Humans revolved around self-enlightenment and the bettering of society as a whole. A Human's moral goal was the achievement of knowledge through peaceful exploration, as recognized in Starfleet's Prime Directive of non-interference with other cultures. (TNG: "First Contact"; VOY: "Equinox", "Equinox, Part II") Humans found a sense of balance in their lives and attitudes. (TNG: "Liaisons") Compassion, courage, and intellect developed into an ideal combination, with ambitions of further self-improvement. (TNG: "Hide and Q")
Another aspect of Human philosophy was the abolition of money. Greed and selfishness had faded on a mass scale as technological progress opened Humanity's possibilities. Earth's economy changed, spurring the creation of the New World Economy. (TOS: "The City on the Edge of Forever"; Star Trek IV: The Voyage Home; Star Trek: First Contact; DS9: "In the Cards"; VOY: "Dark Frontier") Deviations from these ideals were rare and considered abnormal behavior for Humans. (TOS: "Mudd's Women"; VOY: "Equinox", "Equinox, Part II"; ENT: "Fortunate Son")
Many alien cultures found Humanity confusing, due (in part) to the fact that Humans were mostly very hesitant to engage in conflict, but would fight with lethal force as a last resort. (TOS: "By Any Other Name", "Journey to Babel"; TNG: "Allegiance", "Encounter at Farpoint", "The Most Toys"; ENT: "The Forge", "The Aenar"; VOY: "Muse") This inherent conflicting nature made Earth an ideal choice in mediating disputes and finding common ground in interstellar affairs, where the more experienced Vulcans had failed. (ENT: "Babel One", "These Are the Voyages...") It is of note that philosophy courses were not required at Starfleet Academy, but encouraged nonetheless. (TNG: "Samaritan Snare")