Against the Academics

work by Augustine

Also known as: “Contra academicos”

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June 18, 2026

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Against the Academics (386) is an early work by St. Augustine that refutes the skepticism of the Academy. Augustine argued that humans possess certain knowledge, even if they are deceived in many instances. He proposed that we know disjunctive tautologies, such as "Either there is one world or there is not." Additionally, he asserted that we know propositions like "It appears to me that..." and logical truths, such as "If there are four elements, there are not five." Augustine also famously argued that if one is deceived, it is certain that one exists, a concept later echoed by René Descartes with the phrase "If I am deceived, then I exist".123

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skepticism
Medieval skepticism
Augustine’s Contra academicos. Augustine, before his conversion from paganism to Christianity, had found Cicero’s views attractive. But having overcome them through revelation, he characterized his subsequent philosophy as faith seeking understanding. Augustine’s account of skepticism and his answer to it provided the basis of medieval discussions.
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Augustine’s Contra academicos. Augustine, before his conversion from paganism to Christianity, had found Cicero’s views attractive. But having overcome them through revelation, he characterized his subsequent philosophy as faith seeking understanding. Augustine’s account of skepticism and his answer to it provided the basis of medieval discussions.
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St. Augustine
Early writings
…Christian content: Contra academicos (386; Against the Academics), De ordine (386; On Providence), De beata vita (386; On the Blessed Life), and Soliloquia (386/387; Soliloquies). These works both do and do not resemble Augustine’s later ecclesiastical writings and are greatly debated for their historical and biographical significance, but the debates…
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…Christian content: Contra academicos (386; Against the Academics), De ordine (386; On Providence), De beata vita (386; On the Blessed Life), and Soliloquia (386/387; Soliloquies). These works both do and do not resemble Augustine’s later ecclesiastical writings and are greatly debated for their historical and biographical significance, but the debates…
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$optical illusion: refraction of light$
epistemology
St. Augustine
In Against the Academicians (386) he claimed that, if nothing else, humans know disjunctive tautologies such as “Either there is one world or there is not one world” and “Either the world is finite or it is infinite.” Humans also know many propositions that begin with…
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In Against the Academicians (386) he claimed that, if nothing else, humans know disjunctive tautologies such as “Either there is one world or there is not one world” and “Either the world is finite or it is infinite.” Humans also know many propositions that begin with…
Read More