Authors/Ockham/Summa Logicae/Book I/Chapter 22

Latin	English
[1.22. DE COMPARATIONE GENERIS ET SPECIEI AD INVICEM]	[Chapter 22. Of the comparison of genus and species to one another]
Viso quid est genus et quid species, istae intentiones secundum communes proprietates et proprias sunt ad invicem comparandae.	It having been seen what is genus and what is species, those intentions according to common properties and propria should be compared with one another.
Differunt autem in hoc quod genus praedicatur de specie, sed species non praedicatur de genere. Quod non est intelligendum quod species nullo modo praedicetur de genere: hoc enim impossibile est, cum genus praedicetur de specie, et per consequens species de genere. Sequitur enim per conversionem ‘homo est animal, igitur animal est homo’; et ita si genus praedicatur de specie sequitur necessario quod species praedicatur de genere.	Now one difference is that the genus is predicated of the species, but the species is not predicated of the genus. Which is not to be understood as meaning that the species is in no way predicated of the genus, for this is impossible, since the genus is predicated of the species, and as a consequence, the species of the genus. For it follows, by conversion, ‘a man is an animal, therefore an animal is a man’, and so if the genus is predicated of the species it follows necessarily that the species is predicated of the genus.
Et ideo sic intelligenda est differentia quod quando genus actualiter continet sub se diversa individua diversarum specierum tunc genus vere praedicatur de specie universaliter sumpta, sed species tunc non praedicatur de genere universaliter sumpto, quamvis praedicetur de genere particulariter sumpto. Unde haec modo est vera ‘omnis homo est animal’, sed haec est falsa ‘omne animal est homo’, quamvis haec sit vera ‘animal est homo’, ex quo haec particularis, quae cum indefinita convertitur, vera est ‘aliquod animal est homo’.	And therefore the difference should be understood as that when the genus actually contains under it diverse individuals of diverse species, then the genus is truly predicated of the species universally taken, but the species then is not predicated of the genus universally taken, although it may be predicated of the genus, taken in a particular way. Hence ‘every man is an animal’ is now true, but ‘every animal is a man’ is false, although ‘an animal is a man’ is true, from which the particular ‘some animal is a man’, which is converted with the indefinite, is true.
Verumtamen si nullum animal esset in rerum natura nisi homo, haec tunc esset vera ‘omne animal est homo’ sicut ista ‘omnis homo est animal’. Et ita species potest praedicari de genere non tantum particulariter sed etiam universaliter, sed non quando diversa individua diversarum specierum sunt in rerum natura.	Nevertheless if no animal existed in rerum natura except a man, ‘every animal is a man’ would be true, just as ‘every man is an animal’. And thus the species can be predicated of the genus not only in a particular way, but also universally, but not when diverse individuals of diverse species are in rerum natura.
Est etiam advertendum quod quamvis genus praedicetur de specie, praedicatio tamen illa non semper est necessaria, sicut haec non est necessaria ‘homo est animal’. Si enim nullus homo esset, haec esset falsa ‘homo est animal’ sicut haec esset falsa ‘aliquod compositum ex corpore et anima intellectiva est animal’, propter falsam implicationem. Quamvis autem ista sit contingens ‘homo est animal’, ista tamen condicionalis est necessaria ‘si homo est, animal est’.	Also it should be noted that although the genus is predicated of the species, nevertheless, that predication is not always necessary, just as ‘a man is an animal’ is not necessary. For if no man existed, ‘a man is an animal’ would be false, just as ‘some composite of body and intellective soul is an animal’ would be false, on account of the false implication. But although ‘a man is an animal’ is contingent, nevertheless the conditional ‘if a man exists, an animal exists’ is necessary.
Alia differentia ponitur, videlicet quod genus continet speciem, species autem non continet genus. Quod est sic intelligendum quod genus natum est praedicari de pluribus, - hoc enim hic ‘continere’ vocatur -, species autem non potest praedicari de pluribus quam genus suum.	There is another sort of difference, namely, that the genus contains the species, but the species does not contain the genus. Which is to be understand as follows, that the genus is by nature predicated of several things, for this is what ‘contains’ means here, but the species cannot be predicated of more things than its genus.
Alia differentia ponitur quod genus est prius naturaliter quam species. Quae non est intelligenda sicut sonat, quasi prius natura sit illa intentio quae est genus quam illa intentio quae est species, quia illa intentio quae est species potest esse in anima sine illa intentione quae est genus sicut e converso. Unde non quilibet quando format propositionem talem ‘Sortes est homo’ oportet quod habeat omnes intentiones in anima quae sunt genera ad Sortem. Sed per istam propositionem ‘genus est prius natura quam species’ nihil aliud intendunt auctores nisi quod genus est communius quam species.	There is another sort of difference, is that the genus is naturally prior to the species. Which is not to be understood as it sounds, as if before by natura is that intention which is genus, to that intention which is species, because that intention which is species can be in the soul without that intention which is genus, just as conversely. Hence it is not the case that when anyone forms such a proposition as ‘Socrates is a man’, he must have all intentions in the soul which are genera to Socrates. But through the proposition ‘genus is prior by nature to the species’ the authoritative passages mean nothing more than that the genus is more common than the species.
Propter quod non oportet quamvis esse exsistere praedicetur de genere quod praedicetur de qualibet eius specie, immo potest vere negari ab aliqua specie, quamvis vere praedicetur de genere, sed e converso est impossibile. Et hoc non est aliud quam dicere quod tales consequentiae sunt bonae ‘homo est, igitur animal est’, sed non e converso; ‘lapis est, igitur substantia est’ et non e converso.	On account of which it does not have to be the case that although existential being is predicated of the genus, which is predicated of any of its species, although it is truly predicated of the genus, but the converse is impossible. Is this is nothing else than to say that such consequences are good: ‘a man is, therefore an animal is’, but not conversely; ‘a stone is, therefore a substance is’, but not conversely.
Alia differentia ponitur, quae est quod interemptis generibus interimuntur species. Quae non est intelligenda de interemptione reali, sic quod si genus corrumpatur oportet speciem corrumpi realiter et non e converso. Hoc enim falsum est. Quamvis enim haec intentio ‘animal’, quae est genus praedicabile de homine et asino, cesset esse in anima mea et per consequens corrumpatur, non oportet hanc intentionem ‘homo’, quae est species, desinere esse in anima mea.	Another difference is that with the genera totally destroyed, the species are totally destroyed. Which is not to be understood about real destruction, so that if the genus is destroyed, so must the species really be destroyed, and not conversely. For this is false. For although the intention ‘animal’, which is the genus predicable of man and donkey, ceased to be in my soul and in consequence destroyed, it does not have to be that the intention ‘man’, which is species, ceases to be in my soul.
Sed praedicta differentia intelligenda est de interemptione logicali, hoc est: a negatione generis ad negationem Speciei est bona consequentia. Sicut sequitur ‘animal non est, igitur homo non est’, sed e converso non sequitur. Similiter sequitur ‘a non est animal, igitur a non est homo’, sed non e converso. Similiter sequitur ‘nullum animal currit, igitur nullus homo currit’, sed non e converso.	But the difference mentioned above is to be understood abou logical destruction, that is, from the negation of the genus to the negation of the species is a valid consequence. Just as ‘an animal does not exist, therefore a man does not exist’ follows, but the converse does not follow. Similarly ‘a is not an animal therefore a is not a man’ follows, but not conversely. Similarly ‘no animal runs, therefore no man runs’ but not conversely.
Aliae differentiae multae ponuntur, de quibus alibi dixi, et quarum intellectus elici possunt ex dictis et dicendis, ideo de ipsis pertranseo.	There are many other differences, which will be discussed elsewhere, and whose understanding can be elicited from what has been said, and what is to be said. Therefore I will pass over these.
Conveniunt autem genus et species in hoc quod utrumque de pluribus est praedicabile. Quod quidem secundum veritatem theologiae verum est. Quamvis enim non sit nisi unus sol, possunt tamen per divinam potentiam esse plures. Similiter, quamvis non esset nisi unus angelus in una specie, posset tamen Deus, si sibi placeret, producere plures angelos eiusdem speciei, quamvis Philosophus hoc negaret.	But genus and species agree in that both are predicable of several. Which, indeed, is true according to the truth of theology. For although there is only one sun, there can through divine power be several. Similarly, although there were only one angel in one species, God could, if it pleased him, produce several angels of the same species, although the Philosopher denied this.
Ponitur autem alia convenientia inter genus et speciem, scilicet quod utrumque prius est ad illud de quo praedicatur. Quae non est intelligenda sic quod prius in rerum natura sit tam genus quam species quam individuum. Hoc enim falsum est. Potest enim individuum esse sine anima, species autem et genus sine anima esse non possunt. Sed ideo utrumque dicitur prius, quia ab individuo ad genus et speciem est bona consequentia, et non e converso.	But there are supposed to be other agreements between genus and species, namely that each is prior to that of which it is predicated. Which should not be understood as meaning that both genus and species exist in reality, prior to the individual. For this is false. For an individual can exist without a soul, but species and genus cannot exist without a soul. Therefore both are predicated prior, because from individual to genus and species is a good consequence, and not conversely.
Tertia convenientia ponitur quod tam genus quam species est quoddam totum. Quae intelligenda est accipiendo ‘totum’ pro ‘communiori’.	A third agreement is supposed, that genus is a sort of whole, and also species. Which should be understood by understanding ‘whole’ as ‘more common’.