Authors/Ockham/Summa Logicae/Book III-3/Chapter 25

Latin	English
CAP. 25. DE DEFINITIONE DATA PER ADDITAMENTUM.	Chapter 25. On definition given by addendum.
Sequitur videre de definitione data per additamentum. Et est sciendum quod semper in tali definitione debet poni genus definiti cum aliqua differentia accidentali.	It follows to see about the definition given by addendum. And it must be known that in such a definition the genus must always be defined with some accidental difference.
Aliquando tamen aliqua differentia accidentalis in ea posita est propria sibi et aliquando nulla differentia accidentalis est propria sibi. Exemplum primi: si albedo definiatur sic `albedo est color disgregativus visus', nam `disgregativum visus' est differentia accidentalis propria albedini et se cum convertibilis.	Sometimes, however, some accidental difference is placed in it proper to itself, and sometimes no accidental difference is proper to it. An example of the first: if whiteness is defined as `whiteness is the color of disintegrative vision', for `disintegrative vision' is the accidental difference proper to whiteness and is itself convertible with it.
Exemplum secundi: si ternarius definiatur sic `ternarius est numerus impar utrobique primus'; nam `impar' non convertitur cum ternario; nec `utrobique primus', quia convenit binario.	As a secind example: if a ternary is defined as follows: "a ternary is an odd number and first on both sides"; for 'odd' is not converted with ternary; nor `the first on both sides', because it corresponds to the binary.
De tali definitione dantur aliquae regulae.	Some rules are given about such a definition.
Una est quod non debet dari talis definitio per ignotiora, quia talis definitio datur causa innotescendi, nihil autem notificatur per ignotius. ƿ Ex isto autem sequuntur aliquae regulae. Una est quod unum contrariorum non definitur per reliquum; quod est verum de contrariis positivis. Et ratio est, nam licet unum contrariorum aliquando sit perfectius alio, et ita aliquo modo notius secundum naturam, non est tamen tale notius quoad nos; quod tamen requiritur ad definitionem, ex quo definitio datur ut nobis innotescat definitum. Alia regula sequitur, scilicet quod habitus non definitur per privationem, quia semper privatio praesupponit notitiam habitus; et ita privatio non est notior habitu, et per consequens non definit ipsum. Alia regula sequitur, quod permanens non definitur per successivum, quia semper successivum praesupponit notitiam permanentis.	One thing is that such a definition should not be given using unknowns, because such a definition is given for the sake of becoming known, but nothing is known by the unknown. Some rules follow from this. One thing is that one of the opposites is not defined by the other; which is true of positive opposites. And the reason is, for although one of the opposites may sometimes be more perfect than another, and thus in some way better known according to nature, yet such is not better known regarding us; which, however, is required for definition, because definition is given in order to make known to us what is defined. Another rule follows, namely, that habit is not defined by privation, because privation always presupposes knowledge of habit; and thus privation is not better known by habit, and consequently does not define it. Another rule follows, that the permanent is not defined by the successive, because the successive always presupposes the knowledge of the permanent.
Alia regula sequitur, quod oppositum non definitur per oppositum.	Another rule follows, that the opposite is not defined by the opposite.
Quod est verum de oppositis contrarie et de omnibus oppositis absolutis, sed de oppositis privative non est verum, nam semper privatio per habitum definitur. Aliae regulae multa ponuntur V Topicorum circa istam materiam, de quibus ad praesens supersedeo.	This is true of contrary opposites and of all absolute opposites, but it is not true of privative opposites, for privation is always defined by habit. Many other rules are laid down in Topics 5 about this matter, about which I will pass over for the present.