“The soul of man is divided into three parts, intelligence, reason, and passion. Intelligence and passion are possessed by other animals, but reason by man alone.”
As reported by Alexander Polyhistor, and Diogenes Laërtius in Lives and Opinions of Eminent Philosophers, "Pythagoras", Sect. 30, in the translation of C. D. Yonge (1853)
Original
Τὴν δ' ἀνθρώπου ψυχὴν διῃρῆσθαι τριχῆ, εἴς τε νοῦν καὶ φρένας καὶ θυμόν. νοῦν μὲν οὖν καὶ θυμὸν εἶναι καὶ ἐν τοῖς ἄλλοις ζῴοις, φρένας δὲ μόνον ἐν ἀνθρώπῳ.
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Pythagoras 121
ancient Greek mathematician and philosopher -585–-495 BCRelated quotes

“A man is to be cheated into passion, but to be reasoned into truth.”
Religio Laici (1682), Preface.

“Man is to be found in reason, God in the passions.”
K 21
Aphorisms (1765-1799), Notebook K (1789-1793)

[2019, Esoterism as Principle and as Way, World Wisdom, 97, 978-1-93659765-9]
Human being, Specificities

The Myth of Sisyphus (1942), Absurd Creation
Context: In that daily effort in which intelligence and passion mingle and delight each other, the absurd man discovers a discipline that will make up the greatest of his strengths. The required diligence and doggedness and lucidity thus resemble the conqueror's attitude. To create is likewise to give a shape to one's fate. For all these characters, their work defines them at least as much as it is defined by them. The actor taught us this: There is no frontier between being and appearing.

“Sobriety is the strength of the soul, for it preserves its reason unclouded by passion.”
As quoted in The History of Philosophy: From the Earliest Times to the Beginning of the Present Century (1819) by William Enfield
Sobriety is the strength of the mind; for it preserves reason unclouded by passion.
As quoted in Bible of Reason (1831) by Benjamin F. Powell, p. 157
Strength of mind rests in sobriety; for this keeps your reason unclouded by passion.
As quoted in Dictionary of Quotations from Ancient and Modern English and Foreign Sources (1899) by James Wood

Daedalus or Science and the Future (1923)

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 121.

“Behind the perfection of a man's style, must lie the passion of a man's soul.”
Source: Reviews