The School of Athens, Official Page (Vatican Museums)

This source names Aristotle directly: "pointing upward holding his Timaeus, Aristotle beside him with his Ethics, Pythagoras explaining the diatesseron in the foreground, Euclid teaching geometry to his pupils, Ptolemy holding the..."

This source names Athens directly: "own official page for "The School of Athens" in the Room of the Segnatura, naming Plato pointing upward holding his Timaeus, Aristotle beside him with his Ethics, Pythagoras explaining the..."

This source names Diogenes directly: "Zoroaster holding the heavenly sphere, Diogenes lying on the stairs, and a figure believed to be Michelangelo as Heraclitus, confirming the fresco's Bramante-inspired architectural setting and..."

This source names Euclid directly: "the diatesseron in the foreground, Euclid teaching geometry to his pupils, Ptolemy holding the earthly sphere, Zoroaster holding the heavenly sphere, Diogenes lying on the stairs, and a figure..."

This source names Heraclitus directly: "figure believed to be Michelangelo as Heraclitus, confirming the fresco's Bramante-inspired architectural setting and Raphael's own self-portrait among the group."

This source names Vatican Museums directly: "The Vatican Museums' own official page for "The School of Athens" in the Room of the Segnatura, naming Plato pointing upward holding his Timaeus, Aristotle beside him with his Ethics, Pythagoras..."