Aristotle's On Interpretation Ch. 6 : On the simple assertion: A look at the affirmation, the negation and the possibility of contradiction
(17a25-17a36) Ch. 6 On the simple assertion: A look at the affirmation, the negation and the possibility of contradiction
A simple assertion (ἁπλῆ ἀπόφανσις) is a self-contained instance of meaningful speech which combines simple speech instances, i.e. nouns and verbs which hold a meaning of their own. The verb or verb tense in a simple assertion situates the entire assertion either in the present, the past or the future. We count two forms of simple assertion: (i) the affirmation (κατάφασις) and (ii) the negation (ἀπόφασις). A brief review of the ancient Greek terms reveals both of them to be compounds of the word “φάσις”, a broad term, which depending on the context, we render in English as utterance, expression or statement. In turn, the prefixes “κατά-” and “ἀπό-” signify a pointing towards and a pointing away respectively.
(i) an affirmation is an assertion which affirms something of something. For example, when we say “Socrates is wise” we affirm wisdom of Socrates. Conversely, (ii) a negation is an assertion which denies something of something. As such, when we say “Socrates is not wise” we deny wisdom of Socrates.
On what constitutes a contradiction
With an affirmation, we may affirm the being of what is, yet we may also affirm the being of what is not. With a negation we may deny the being of what is not, yet also deny the being of what is. Therefore, we may state that any one thing we may affirm, we may also deny and that for every possible affirmation, there exists a coordinate, opposite (αντικείμενη) negation and vice versa. (Aristotle also discusses this in Cat. Ch. 10 13a37-13b11)
A pair of opposite assertions we call a contradiction (ἀντίφασις). To elaborate on this, for two assertions to constitute a contradiction one must affirm and the other deny the same thing of the same thing not just in name but also in definition, i.e. synonymously as opposed to homonymously. By way of illustration, the assertions “Nicomachus is healthy” and “Nicomachus is not healthy” only constitute a contradiction if they both refer to health as a quality in the same way (e.g. as natural capacity as opposed to just a condition) and either affirm it or deny it of the same Nicomachus (e.g. the son of Aristotle as opposed to any other Nicomachus).
We have no contradiction unless this requirement is met. To consider the above example, if the assertion “Nicomachus is healthy” refers to health in the sense of condition and not of a natural capacity, while the assertion “Nicomachus is not healthy” refers to it as natural capacity, then the two assertions do not contradict. Likewise, if the latter assertion happens to refer to Nicomachus the father of Aristotle and the former refers to his son, then the two assertions do not contradict.
Key points: (i) a simple assertion (ἁπλῆ ἀπόφανσις) is a self-contained instance of meaningful speech which comes about through the combination of nouns and verbs. (ii) A simple assertion is either an affirmation (κατάφασις) or a negation (ἀπόφασις). The former affirms something of something, the latter denies something of something. (iii) With an affirmation we may affirm the existence both of what exists and what does not exist. Further, with a negation we may deny the existence of what does not exist and what exists. (iv) We may therefore have two assertions one denying and the other affirming the same thing of the same thing. Such a pair of assertions we call a contradiction.
