Authors/Ockham/Summa Logicae/Book I/Chapter 26

Latin	English
[CAP. 26. DE DEFINITIONE: QUOT MODIS DICITUR DEFINITIO?]	[26: On definition: in how many ways is it defined?]
(1) Quoniam logici non solum utuntur praedictis vocabulis secundae intentionis, sed etiam multi termini alii secundae intentionis et etiam secundae impositionis frequenter in usum veniunt, ne studentes per ignorantiam significationis eorum in inquisitione veritatis retardentur, volo nunc compendiose de aliquibus eorum ad instructionem simplicium pertractare.	Since logicians not only use the previously mentioned words of second intention, and [since] also many other terms of second intention, and also of second imposition, frequently come into use, I wish now briefly to deal with some of them for the instruction of the simple, lest students be slowed down in their search for truth through ignorance of their signification.
(2) Terminorum autem quibus utuntur logici quidam sunt communes omnibus universalibus, quidam sunt proprii aliquibus eorum, quidam competunt aliquibus eorum simul acceptis, quidam competunt uni respectu alterius. Termini qui competunt pluribus simul acceptis sunt ut definitio et descriptio.	Now of the terms logicians use, some are common to all universal [terms], some are proper to some of them, some belong to some of them taken together, some belong to one with respect to another. The terms that belong to several taken together as ‘definition’ and ‘description’.
(3) Definitio autem dupliciter accipitur. Quaedam est definitio exprimens quid rei et quaedam est definitio exprimens quid nominis.	Now ‘definition’ is taken in two senses. One is a real definition, and one is a nominal definition.
(4) Definitio exprimens quid rei dupliciter accipitur, scilicet large, et sic comprehendit definitionem stricte sumptam et etiam descriptivam definitionem. Aliter accipitur hoc nomen 'definitio' stricte, et sic est sermo compendiosus, exprimens totam naturam rei, nec aliquid extrinsecum rei definitae declarans.	Real definition is taken in two senses, namely broadly – and thus it comprehends ‘definition’ strictly taken and also descriptive definition. In another way it is taken strictly, and thus is a short expression expressing the whole nature of the thing, not clarifying something extrinsic to the thing defined.
(5) Hoc autem dupliciter fieri potest. Nam quandoque in tali sermone ponuntur casus obliqui exprimentes partes rei essentiales, sicut si definiam hominem sic dicendo 'homo est substantia composita ex corpore et anima intellectiva'; isti enim obliqui 'corpore et anima intellectiva' partes rei exprimunt. Et ista potest vocari definitio naturalis.	But this can be taken in two ways. For sometimes in such expressions there are oblique cases expressing the essential parts of the thing, e.g. if I define ‘man’ saying ‘a man is a substance composed of body and intellective soul’ – for the oblique expressions ‘body and intellective soul’ express parts of the thing. And this can be called a ‘natural definition’
(6) Alia est definitio in qua nullus ponitur casus obliquus, sed ponitur genus in recto et similiter in recto ponitur differentia, vel ponuntur differentiae exprimentes partes rei definitae, ad modum quo 'album' exprimit albedinem. Et ideo sicut 'album' quamvis exprimat albedinem non tamen supponit pro albedine sed tantum pro subiecto albedinis, ita differentiae illae quamvis exprimant partes rei non tamen supponunt pro partibus rei sed praecise pro toto composito ex partibus illis.	The other is a definition in which no oblique case occurs, but the genus is given directly, and similarly the differentia is given directly, or the differentiae expressing the parts of the thing defined are given directly, in the way that ‘white’ expresses whiteness. And therefore just as ‘white’ – although it expresses whiteness – still does not supposit for whiteness but only for the subject of whiteness, so that those differentiae, although they express the parts of the thing, still do not supposit for the parts of the thing but precisely for the whole composed from those parts.
Talis est ista definitio hominis 'animal rationale' vel ista 'substantia animata sensibilis rationalis'. Nam istae differentiae 'animata', 'sensibilis', 'rationalis' supponunt pro homine, quia homo est rationalis, animatus et sensibilis, tamen important partem hominis, sicut abstracta correspondentia eis important partem vel partes hominis, quamvis non eodem modo. Et ista potest vocari definitio metaphysicalis, quia sic metaphysicus definiret hominem.	Such is the definition ‘rational animal’ of man, or ‘rational sensitive animated substance’. For the differentiae ‘animated’, ‘sensitive’, ‘rational’ supposit for a man, because a man is rational, animated and sensitive, yet they convey a part of a man, just as abstract [terms] corresponding to them convey a part (or parts) of a man, although not in the same way. And this can be called a ‘metaphysical’ definition, because a metaphysician would define a man in this way.
(7) Sed praeter istas duas definitiones nulla potest esse alia nisi forte illa cuius quaelibet pars est in plus et totum aequale. Et ideo truffaticum est illud quod dicunt aliqui quod hominis quaedam est definitio logicalis, quaedam naturalis, quaedam metaphysicalis; quia logicus cum non tractet de homine, eo quod non tractat de rebus quae non sunt signa, non habet hominem definire, sed habet docere quomodo aliae scientiae tractantes de homine ipsum definire debent.	But beyond those two definitions there can be nothing more, other than perhaps that of which any part is in more, and the whole equal. And thus what some persons say - that one definition of man is logical, another natural, another metaphysical - is frivolous. For the logician, since he does not treat of man (in that he does not treat of things that are not signs) does not have to define man, but has to teach how other sciences dealing with man should define him.
Et ideo logicus nullam definitionem hominis assignare debet, nisi forte gratia exempli, et tunc illa definitio quae gratia exempli ponitur debet esse naturalis vel rnetaphysicalis.	And therefore, the logician ought not assign any definition of man, except perhaps by way of example, and then that definition which is given for sake of example ought to be a natural one or a metaphysical one.
(8) Et sicut vanum est dicere quod quaedam est definitio naturalis, quaedam metaphysicalis, quaedam logicalis, ita vanum est dicere quod quidam homo est naturalis, quidam metaphysicalis, quidam logicalis.	And just as it is in vain to say that one definition is natural, another metaphysical, another logical, so it is pointless to say that one of man is physical, another metaphysical, another logical.
(9) Et similiter, quamvis posset dici quod quaedam definitio hominis est naturalis, quaedam metaphysicalis propter diversitatem partium istarum orationum, tamen totaliter irrationale et falsum est ponere quod quidam homo est naturalis, quidam metaphysicalis. Nam si sit quidam homo naturalis, quidam metaphysicalis, aut intelligitur quod est aliqua res extra animam et vera substantia quae est homo naturalis, et alia vera substantia quae est homo metaphysicalis, aut intelligitur quod aliquis conceptus mentis vel vox est homo naturalis et alius metaphysicalis.	Likewise, even though it could be said that one definition of man is physical, another metaphysical, on account of the difference in the parts of these expressions, nevertheless it is totally unreasonable and false to suppose claim that one kind of man is physical, another metaphysical. For if one kind of man is physical, another kind metaphysical, either it is understood that there is some thing outside the soul, a true substance that is a physical man, and another true substance that is a metaphysical man, or it is understood that one concept of the mind or utterance is a physical man and another one is metaphysical.
(10) Primum dari non potest, quia quaero. quomodo illi homines qui sunt substantiae distinguuntur? Aut unus est pars alterius, aut sunt quaedam tota secundum se tota distincta, aut aliquid est pars utriusque, quamvis non omne quod est pars unius sit pars alterius. Primum et secundum dari non possunt, sicut evidenter patet. Nec tertium dici potest, quia cum homo naturalis non componatur nisi ex materia et forma, oporteret quod vel materia vel forma non esset pars alterius illorum hominum, et tunc alter illorum, scilicet homo metaphysicalis vel naturalis esset materia tantum vel forma tantum, quod est absurdum.	The first cannot be granted, because I ask how those men, who are substances, are distinguished. Either one is a part of the other, or they are certain wholes in themselves wholly distinct, or something is a part of both , although not everything that is a part of the one is a part of the other. The first and second cannot be granted, as is evidently clear. Nor can the third be said, because since a physical man is composed only of matter and form, it would have to be that either matter or form would not be a part of the other of those men. And then one of them, that is, the metaphysical or the physical one, would be only matter or only form, which is absurd.
(11) Nec valet dicere quod aliter considerat metaphysicus hominem et aliter naturalis, et propter hoc homo consideratus a metaphysico distinguitur ab homine considerato a naturali. Quia quamvis ita esset, ex hoc non sequeretur quod unus homo esset metaphysicalis et alius naturalis, sed sequeretur quod tantum esset diversa consideratio eiusdem hominis. Sicut si Socrates videat Platonem clare et Socrates obscure, quamvis visio unius et alterius sit diversa, tamen Plato visus non est alius, ita quamvis consideratio naturalis de homine et metaphysicalis sit alia, tamen homo consideratus non est alius. Sic igitur non est alia res quae sit homo naturalis et alia quae sit homo metaphysicalis.	Nor is it valid to say that the metaphysician considers man in one way, and the natural philosopher in another, and that because of this, man considered by the metaphysician is distinguished from man considered by the natural philosopher. For even if that were so, it would not follow from this that one man would be a metaphysical and another naturalistic, but rather it would follow that there would be only a diverse consideration of the same man. For example, if Socrates sees Plato clearly but Socrates obscurely, then even though the vision of one is different from the vision of the other, nevertheless the Plato who is seen is not different. So, even though the natural philosopher’s consideration of man and the consideration of the metaphysician, are different, nevertheless the man considered is not different. So, therefore, there is not one thing that is a natural man and another that is a metaphysical.
(12) Nec potest dici quod sit alius conceptus vel vox, quia iste conceptus vel erit definitio vel pars definitionis vel aliquod praedicabile de homine, et patet quod quidquid dicatur, nihil est ad propositum.	Nor can it be said that the concept or utterance is different, for the concept will either be a definition or a part of a definition or something predicable of man, and it is clear that whatever is given, it is in no way relevant to the case in hand.
(13) Ex quibus omnibus constat quod definitiones possunt esse distinctae, quamvis definitum sit idem. Verumtamen licet definitiones sint distinctae, tamen illae definitiones idem significant, et quidquid significatur per unam vel per partem unius significatur per aliam vel per partem alterius, quamvis partes differunt in modo significandi, quia aliqua pars unius est alterius casus a parte alterius.	From these considerations, it is clear that definitions can be distinct even though the thing defined is the same. Yet although the definitions are distinct, nevertheless those definitions signify the same, and whatever is signified by the one, or by part of one, is signified by the other, or by part of the other, although the parts differ in their mode of signifying because some part of one is in a different case from the corresponding part of the other.
(14) Est autem sciendum quod quamvis de quocumque praedicatur definitito significative sumpta de eodem praedicatur definitum significative sumptum et e converso, et quamvis aliqua propositio composita ex definitione et definito hypothetica et etiam de possibili vel aequivalens tali sit necessaria, sicut ista est necessaria 'si homo est, animal rationale est' et e converso, et similiter ista 'omnis homo potest esse animal rationale' - sumendo subiectum pro eo quod potest esse - et e converso, tamen nulla propositio talis affirmativa mere de inesse et mere de praesenti est necessaria. Unde ista est simpliciter contingens 'homo est animal rationale' sicut ista 'homo est substantia composita ex corpore et anima intellectiva', et hoc quia si nullus homo esset, quaelibet talis esset falsa. Verumtamen Aristoteles qui ponit quod tales sunt necessariae 'homo est animal', 'asinus est animal', poneret quod tales sunt necessariae.	Now you should know that, even though the thing defined, taken significatively, is predicated of whatever the definition taken significatively is predicated of, and conversely, and although a hypothetical proposition composed of the definition and the thing defined is necessary, and even a de possibili proposition or a proposition equivalent to such a proposition (just as ‘If it is a man, it is a rational animal’ is necessary, and conversely, and likewise ‘Every man can be a rational animal’, taking the subject for that which can be a man, and conversely) nevertheless no such affirmative merely assertoric proposition merely in the present tense is necessary. Hence, ‘A man is a rational animal’ is absolutely contingent, as is ‘A man is a substance composed of a body and an intellective soul’. And this is because if no man existed, each such proposition would be false. Nevertheless Aristotle, who claims that ‘A man is an animal’, and ‘An ass is an animal’ are necessary, would maintain that such propositions are necessary.
(15) Ex praedictis colligi potest quod definitio non est eadem cum definito, quia, secundum omnes, definitio est sermo vel mentalis vel vocalis vel scriptus, et per consequens non est eadem realiter cum re nec cum una dictione. Verumtamen definitio significat idem quod definitum. Et sic intelligunt recte loquentes quando dicunt quod definitio et definitum sunt idem realiter, hoc est significant idem.	From the considerations above it can be gathered that the definition is not the same as the thing defined, for, according to all, the definition is a discourse, either mental or spoken or written, and as a consequence is not really the same as a thing, or as a single word. Nevertheless, a definition signifies the same thing as the defined. And so those who say that a definition and the defined are really the same - that is, they signify the same - correctly understand the matter when they say this.
(16) Sciendum est autem quod definitio sic stricte sumpta non est nisi solius substantiae tamquam rei expressae per definitionem, et ideo accipiendo definitum pro nomine convertibili cum definitione, talis definitio non est nisi nominum, non verborum nec aliarum partium orationis.	But it should be known that ‘definition’ – strictly and broadly taken in this way – is only of substance, as a thing expressed by the definition, and therefore in taking the thing defined for a name convertible with the definition, such a definition is only of names, and not of verbs nor of other parts of speech.
(17) Definitio autem exprimens quid nominis est oratio explicite declarans quid per unam dictionem importatur, sicut aliquis volens docere alium quid significat hoc nomen 'album' dicit quod significat idem quod haec oratio 'aliquid habens albedinem'. Et ista definitio potest esse nominum, non solum illorum de quibus potest vere affirmari esse in rerum natura sed etiam illorum de quibus talis praedicatio est impossibilis. Et sic 'vacuum', 'non ens', 'impossibile', 'infinitum', 'hircocervus' habent definitiones, hoc est istis nominibus correspondent aliquae orationes significantes idem quod istae dictiones.	But a nominal definition is an expression explicitly setting out what is conveyed by one expression. For example, someone wanting to say to another what the name ‘white’ signifies, says that it signifies the same as the expression ‘something having whiteness’. And that definition can be of names, not only of those things of which being can be truly be affirmed in reality, but also of those of which such predication [i.e. being] is impossible. And thus ‘vacuum’, ‘non being’, ‘impossible’, ‘infinite’, ‘chimera’ have definitions, i.e. to those names there correspond certain expressions signifying the same.
(18) Ex quo sequitur quod sic accipiendo definitionem aliquando praedicatio definitionis de definito per hoc verbum 'est', utroque significative sumpto, est impossibilis, sicut haec est impossibilis 'chimaera est animal compositum ex capra et bove'; sit haec eius definitio. Et hoc propter implicationem impossibilem, qua scilicet implicatur aliquid compositum ex capra et bove. Tamen ista propositio in qua illi termini matertaliter supponunt chimaera' et 'animal compositum ex capra et bove' idem significant' vera est.	From which it follows that in taking ‘definition’ in this way, sometimes the predication of the definition of the defined using the verb ‘is’, both taken significatively, is impossible – just as ‘a chimera is an animal composed from a goat and an ox’ (if that is its definition) is impossible. And this [is] because of the impossible implication, namely by which something composed of a goat and an ox is conveyed [to exist]. Yet the proposition “‘chimera’ and ‘animal composed from a goat and an ox’ signify the same”, where those terms have material supposition, is true.
Et per illam primam communiter loquentes intelligunt istam secundam, quae tamen secundum proprietatem sermonis alia est. Unde sicut, secundum Priscianum, frequenter una dictio ponitur pro alia, sicut exemplificat in I Constructionum, ita frequenter una oratio pro alia ponitur. Verumtamen condicionalis ex tali definito et definitione composita vera est. Ista enim vera est 'si aliquid est chimaera, ipsum est compositum ex homine et leone' et e converso.	And by that first commonly speakers understand the second, which nevertheless according to propriety of speech is something else. Therefore, just as, according to Priscian, frequently one expression is given for another, as is exemplified in Constructions I, so also frequently on sentence is given for another. Nevertheless a conditional [statement] composed from such a definition, and such a defined, is true. For ‘if something is a chimera, it is composed from a man and a lion’ is true, and conversely.
(19) Non solum autem nomina possunt definiri definitione tali, sed etiam omnes partes orationis sic possunt definiri, scilicet verba, coniunctiones etc. Sic definiuntur talia adverbia 'ubi' 'quando', 'quot', coniunctiones et huiusmodi. Et tunc non debet definitio praedicari de definito mediante hoc verbo 'est', utroque significative sumpto, sed hoc totum 'idem significare' vel aliquid tale debet de illis, materialiter sumpis, verificari; vel alia oratio debet de illo verificari, ipso materialiter sumpto, sic dicendo 'ubi: est adverbium interrogativum loci', 'quando: est adverbium interrogativum temporis', et sic de aliis.	Now not only names can be defined by such a [nominal] definition, but also all the parts of speech can be defined in this way, namely, verbs, conjunctions, etc. Adverbs like ‘where’, ‘when’, ‘as many’, conjunctions, and so on, are defined in this way. And then the definition ought not to be predicated of the defined by the intermediary verb ‘is’ when both are taken significatively. Rather the whole expression ‘to signify the same’, or some such expression, should be verified of those terms taken materially, or else another expression should be verified of the defined when it is taken materially, by saying ‘Where is an interrogative adverb of place’, ‘When is an interrogative adverb of time’, and so on.