Editing Cleanthes (section)

==Philosophy==
Cleanthes was an important figure in the development of Stoicism, and stamped his personality on the physical speculations of the school, and by his [[materialism]] gave a unity to the Stoic system.<ref>{{Harvnb|Davidson|1907|p=27}}</ref>
He wrote some fifty works, of which only fragments have survived, preserved by writers such as [[Diogenes Laërtius]], [[Stobaeus]], [[Cicero]], [[Seneca the Younger|Seneca]] and [[Plutarch]].

===Physics===
Cleanthes revolutionized [[Stoic physics]] by the theory of tension (''tonos'') which distinguished Stoic materialism from all conception of matter as dead and inert.<ref>{{Harvnb|Hicks|1910|p=7}}</ref> He developed Stoic [[pantheism]], and applied his materialistic views to [[logic]] and [[ethics]].<ref>{{Harvnb|Davidson|1907|p=28}}</ref> Thus he argued that the [[Soul (spirit)|soul]] was a material substance, and that this was proved (a) by the circumstance that not only bodily qualities, but also mental capacity, are transmitted by ordinary generation from parent to child; and (b) by the sympathy of the soul with the body seen in the fact that, when the body is struck or cut, the soul is pained; and when the soul is torn by anxiety or depressed by care, the body is correspondingly affected.<ref>{{Harvnb|Davidson|1907|p=95}}</ref> Cleanthes also taught that souls live on after death, but that the intensity of its existence would vary according to the strength or weakness of the particular soul.<ref>Plutarch, ''Plac. Phil.'' iv. 7.</ref>

Cleanthes regarded the [[Sun]] as being [[Divinity|divine]];<ref>Cicero, ''De Natura Deorum'', ii. 15.</ref> because the Sun sustains all living things, it resembled the divine fire which (in Stoic physics) animated all living beings, hence it too must be part of the vivifying fire or aether of the universe. Some maintain that he accused [[Aristarchus of Samos|Aristarchus]] of impiety for daring to put into motion "the hearth of the universe" (i.e. the [[Earth]]); this interpretation depends on an emendation of the received text,<ref>Plutarch, ''On the face of the orb of the Moon'', 922F–923A</ref> since in the manuscripts it is Aristarchus that did the accusing.{{sfn|Russo|Medaglia|1996|pp=113–121}} The largest surviving fragment of Cleanthes is the portion of the ''Hymn to Zeus'',<ref>{{harvnb|Ellery|1976}}; {{harvnb|Rolleston|1890|pp=1–2, 129}}</ref> which has been preserved in [[Stobaeus]], in which he declares praise and honour of [[Zeus]] to be the highest privilege of all rational beings.<ref>{{Harvnb|Hicks|1910|pp=96–97}}</ref>

===Ethics===
Cleanthes maintained that pleasure is not only not a good, but is "contrary to nature" and "worthless."<ref name="davidson148">{{Harvnb|Davidson|1907|p=148}}</ref> It was his opinion that the [[Stoic passions|passions]] (love, fear, grief) are weaknesses: they lack the strain or tension which he persistently emphasized, and on which the strength of the soul, no less than that of the body, depends, and which constitutes in human beings self-control, and moral strength, and also conditions every virtue.<ref name="davidson148"/> He said in a striking passage: "People walk in wickedness all their lives or, at any rate, for the greater part of it. If they ever attain to virtue, it is late and at the very sunset of their days."<ref>{{Harvnb|Hicks|1910|p=89}}</ref>

Zeno had said that the goal of life was "to live consistently," the implication being that no life but the passionless life of reason could ultimately be consistent with itself. Cleanthes is credited with having added the words "with nature," thus completing the well-known Stoic formula that the goal is "to live consistently with nature."<ref>{{Harvnb|Stock|1908|p=7}}</ref> For Cleanthes, this meant, in the first place, living conformably to the course of the universe; for the universe is under the governance of reason, and everyone has it as their privilege to know or become acquainted with the world-course, to recognize it as rational and cheerfully to conform to it.<ref name="davidson143">{{Harvnb|Davidson|1907|p=143}}</ref> This, according to him, is true freedom of will not acting without motive, or apart from set purpose, or capriciously, but humbly acquiescing in the universal order, and, therefore, in everything that befalls one.<ref name="davidson143"/> The direction to follow [[Logos|Universal Nature]] can be traced in his famous prayer:
{{poemquote|Lead me, [[Zeus]], and you too, [[Destiny]],
To wherever your decrees have assigned me.
I follow readily, but if I choose not,
Wretched though I am, I must follow still.
Fate guides the willing, but drags the unwilling.<ref>Epictetus, ''Enchiridion'', 53; Seneca, ''Epistles'', cvii, 11. The fifth line is not found in Epictetus.</ref>}}