Source edition
Aristotle. Aristotelis Opera, Volume 1. Bekker, Immanuel, editor. Oxford: Oxford University Press, 1837.
Source data
A Digital Corpus for Graeco-Arabic Studies · CC BY-SA 4.0
Cloned and adapted by Humanitext, with ongoing edits.
Summary
This work is a foundational treatise in logic and the philosophy of language, systematically examining the meaning of words, the structure of propositions, and the relations of truth, falsity, and opposition. Aristotle begins by defining nouns and verbs as conventional signs that, when combined, form declarative sentences capable of being true or false, thereby establishing the basic concepts of affirmation, denial, contradiction, and contrariety. He then addresses the famous puzzle of future contingents, arguing against determinism by showing that future events retain potentiality and are not yet definitively true or false. The discussion progresses to the complexity of combining multiple terms and the logical relations, such as opposition and implication, among modal propositions involving possibility and necessity. Finally, by examining the opposition of beliefs in the mind, Aristotle demonstrates that the true contrary to a proposition is not a contrary affirmation but rather its negation, revealing the ultimate nature of logical opposition.