A Plutarch essay asking whether cold is a real substance opposed to heat, or merely the absence of heat, and which element (air, water, or earth) is primarily cold.
De Primo Frigido ("On the Principle of Cold") is a short natural-philosophical essay addressed to Plutarch's friend Favorinus. It opens with a single question: is there some primary substance of cold, the way fire is the substance of heat, or is coldness merely a privation of heat, as darkness is said to be a privation of light? Plutarch works through this in the manner of a Peripatetic disputation, weighing physical evidence — shivering, freezing water, the coldness of breath blown through pursed lips — against the logical claim that a mere absence cannot itself act on bodies or admit of degree the way cold clearly does (some things are colder than others, which a true privation could never be).
Having argued that cold is a real, positive power and not a mere absence, Plutarch turns to the harder question of which of the four elements is primarily cold. He surveys the views of earlier thinkers: the Stoics assign primary coldness to air, Empedocles and Strato to water, and Plutarch himself builds a case, drawing on Homer and Hesiod as well as observations about freezing rivers, ice, and deep well-water, for treating earth as the true seat of coldness, with air and water being cold only by derivation from it. Along the way he ranges through etymology (the Greek words for mist, gloom, and Tartarus), poetic quotation, and everyday physical observation — oil freezing less readily than water because of the air mixed into it, deep rocks radiating a cold that startles those who touch them.
The essay matters less for reaching a firm conclusion than for showing Plutarch's method: he explicitly declines to assert certainty at the end, saying it is more philosophical to withhold assent on unclear matters. It is a good example of the tradition of physical/causal inquiry Plutarch inherited from the Peripatos and Academy, testing rival elemental theories against sensory evidence, poetic authority, and logical argument about privation versus substance.
“For indeed there is no mixture of a state with its privation, nor does any power admit into itself the privation opposed to it when it approaches, nor make it a partner, but rises up against it instead”
— De Primo Frigido · read this chapter →
“the Stoics assigning primary coldness to air, Empedocles and Strato to water; though someone else might perhaps show earth to be the cause of coldness”
— De Primo Frigido · read this chapter →
“just as air is dark when light is lacking, so, when heat has departed, what remains is cold air, and nothing else”
— De Primo Frigido · read this chapter →
“A sign of this is found even here, in the case of rocks: for a great cold rises up from the depths, one not easy to bear when it strikes”
— De Primo Frigido · read this chapter →
“considering it more philosophical to withhold assent in matters that are unclear”
— De Primo Frigido · read this chapter →
It is a short essay addressed to Favorinus asking whether cold is a real, positive substance (like fire is for heat) or merely the absence of heat, and then arguing over which element — air, water, or earth — is the true primary source of cold.
No. He argues cold cannot be a mere privation because privations like blindness or death do not vary in degree, whereas things clearly vary in how cold they are, and cold produces distinct effects on bodies rather than simply marking heat's absence.
He reviews the Stoic view (air) and the Empedocles/Strato view (water), then argues for earth, citing evidence such as deep well-water and rock being colder than surface air or water, and earth's inherent fixity and density.
Favorinus is the friend to whom Plutarch addresses the essay; the piece is framed as a direct argument laid out for him to weigh against other philosophers' views, and Plutarch invites him to compare the arguments rather than treat them as settled.
He quotes Homer and Hesiod — for instance Hesiod's phrase 'misty Tartarus' and Homeric lines calling darkness 'air' — as evidence that the ancients associated air with both darkness and cold, using poetic diction as a form of testimony in his physical argument.
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