(2) But, as your question now stands, with respect to the peculiarities by which these genera are separated, you alone speak of the peculiarities of energies. Hence you inquire concerning the difference in the last things pertaining to them; but you leave uninvestigated such things as are first, and most honourable in them, and which are the elements of their difference. In the same place, also, something is added concerning “ efficacious and passive motions ,” which is a division by no means adapted to the difference of the more excellent genera. For the contrariety of action and passion is not inherent in any one of them; but their energies are unrestrained, immutable, and without habitude to their opposites. Hence, neither must we admit in them motions of such a kind as arise from action and passion. For neither do we admit in the soul a self-motion, which consists of the mover and that which is moved; but we conceive that it is a certain simple essential motion, subsisting from itself, and not possessing a habitude to another thing, and exempt from acting on, and suffering from, itself. Who, therefore, can endure that the peculiarities of the genera superior to the soul, should be distinguished according to active or passive motions?

(24) Now in definitions, difference is assumed, which, in the definition, occupies the place of sign. The faculty of laughing, accordingly, being added to the definition of man, makes the whole - a rational, mortal, terrestrial, walking, laughing animal. For the things added by way of difference to the definition are the signs of the properties of things; but do not show the nature of the things themselves. Now they say that the difference is the assigning of what is peculiar; and as that which has the difference differs from all the rest, that which belongs to it alone, and is predicated conversely of the thing, must in definitions be assumed by the first genus as principal and fundamental.

(11) We divide, therefore, the genus of what is proposed for consideration into the species contained in it; as, in the case of man, we divide animal, which is the genus, into the species that appear in it, the mortal, and the immortal. And thus, by continually dividing those genera that seem to be compound into the simpler species, we arrive at the point which is the subject of investigation, and which is incapable of further division.

(1) And all dependent from Above are subdivided into species in the fashion which I am to tell. The genera of all things company with their own species; so that the genus is a class in its entirety, the species is part of a genus. The genus of the Gods will, therefore, make the species of the Gods out of itself. In like way, too, the genus of the daimons, and of men, likewise of birds, and of all [animals] the Cosmos doth contain within itself, brings into being species like itself. There is besides a genus other than the animal,—a genus, or indeed a soul, in that it’s not without sensation,—in consequence of which it both finds happiness in suitable conditions, and pines and spoils in adverse ones;—I mean [the class] of all things on the earth which owe their life to the sound state of roots and shoots, of which the various kinds are scattered through the length and breadth of Earth.

(19) The species is always contemplated in a part. On the other hand, however, if a thing is part of another, it will not be also a species. For the hand is a part of a man, but it is not a species. And the genus exists in the species. For [the genus] is both in man and the ox. But the whole is not in the parts. For the man is not in his feet. Wherefore also the species is more important than the part; and whatever things are predicated of the genus will be all predicated of the species.

(438) And so of more and less, and of other correlative terms, such as the double and the half, or again, the heavier and the lighter, the swifter and the slower; and of hot and cold, and of any other relatives;—is not this true of all of them? Yes. And does not the same principle hold in the sciences? The object of science is knowledge (assuming that to be the true definition), but the object of a particular science is a particular kind of knowledge; I mean, for example, that the science of house-building is a kind of knowledge which is defined and distinguished from other kinds and is therefore termed architecture. Certainly. Because it has a particular quality which no other has? Yes. And it has this particular quality because it has an object of a particular kind; and this is true of the other arts and sciences? Yes. Now, then, if I have made myself clear, you will understand my original meaning in what I said about relatives. My meaning was, that if one term of a relation is taken alone, the other is taken alone; if one term is qualified, the other is also qualified. I do not mean to say that relatives may not be disparate, or that the science of health is healthy, or of disease necessarily diseased, or that the sciences of good and evil are therefore good and evil; but only that, when the term science is no longer used absolutely, but has a qualified object which in this case is the nature of health and disease, it becomes defined, and is hence called not merely science, but the science of medicine. I quite understand, and I think as you do.

(1) With respect to your inquiry, “ what the peculiarities are in each of the more excellent genera, by which they are separated from each other? ” if you understand by peculiarities the specific differences under the same genus, which are distinguished by opposite qualities, as the rational and irrational under animal; we by no means admit peculiarities of this kind, in things which neither have one common essence, nor an equal contradistinction, nor receive a composition from something common, which is indefinite, and defines the peculiarity. But if you apprehend the peculiarity to be, as in prior and secondary natures, differing in their whole essence and whole genus, a certain simple condition of being, definite in itself; in this case, your conception of peculiarities will be reasonable. For these peculiarities of things, which have an eternal subsistence, are simple, and entirely exempt. The inquiry, however, proceeds imperfectly. For it was necessary, in the first place, to inquire what the peculiarities are of the more excellent genera, according to essence; in the next place, what they are according to power; and thus afterwards, what they are according to energy.

(9) Accordingly we must first take the genus, in which are the points that are nearest those above; and after this the next difference. And the succession of differences, when cut and divided, completes the "What it is." There is no necessity for expressing all the differences of each thing, but those which form the species.

(1) But neither must we admit that cause of the distinction of these genera which you subjoin, viz. “ that it is an arrangement with reference to different bodies; as, for instance, of Gods to etherial bodies, but of dæmons to aerial bodies, and of souls to such as are terrene .” For such an arrangement as this, which resembles that of Socrates to a tribe, when he is a senator, is unworthy of the divine genera, because all of them are essentially unrestrained and free. To which may be added, that it is dreadfully absurd to ascribe to bodies a principal power of giving a specific distinction to the first causes of themselves. For bodies are in servile subjection to these causes, and are ministrant to generation. And farther still, the genera of the more excellent natures are not in bodies, but the former externally rule over the latter. Hence they are not changed in conjunction with bodies. Again, they impart from themselves to bodies every such good as they are able to receive, but they themselves receive nothing from bodies; so that neither will they derive from them certain peculiarities.

(5) And, again, of the things contained under these ten Categories, some are Univocal, as ox and man, as far as each is an animal. For those are Univocal terms, to both of which belongs the common name, animal; and the same principle, that is definition, that is animate essence. And Heteronyms are those which relate to the same subject under different names, as ascent or descent; for the way is the same whether upwards or downwards. And the other species of Heteronyms, as horse and black, are those which have a different name and definition from each other, and do not possess the same subject. But they are to be called different, not Heteronyms. And Polyonyms are those which have the same definition, but a different name, as, hanger, sword, scimitar. And Paronyms are those which are named from something different, as "manly" from "manliness."

(6) Equivocal terms have the same name, but not the same definition, as man -both the animal and the picture. Of Equivocal terms, some receive their Equivocal name fortuitously, as Ajax, the Locrian, and the Salaminian; and some from intention; and of these, some from resemblance, as man both the living and the painted; and some from analogy, as the foot of Mount Ida, and our foot, because they are beneath; some from action, as the foot of a vessel, by which the vessel soils, and our foot, by which we move. Equivocal terms are designated from the same and to the same; as the book and scalpel are called surgical, both from the surgeon who uses them and with reference to the surgical matter itself.

(3) This little chapter is not without its special difficulty. Are we to read as a word implying motion, with as its determinative, or as implying invocation, with as its determinative? The copyists differed and some of them changed the word into so that there should be no ambiguity. But this does not clear up the words which immediately follow; hence Ba has suppressed them, whilst other copyists have given themselves no trouble as to the sense of what they wrote

(22) For each of the species is either an essence; as when we say, Some substances are corporeal and some incorporeal; or how much, or what relation, or where, or when, or doing, or suffering.

(1) After these things, you again subjoin another division for yourself, “ in which you separate the essences of the more excellent genera by the difference of passive and impassive .” But neither do I admit this division. For no one of the more excellent genera is passive, nor yet impassive in such a way as to be contradistinguished from that which is passive; nor is naturally adapted to receive passions, but liberated from them through virtue, or some other worthy condition of being. But because they are entirely exempt from the contrariety of action and passion; and because they are not at all adapted to suffer, and have essentially an immutable firmness, on this account I place the impassive and the immutable in all the divine genera.

(3) For Plato calls plants animals, as partaking of the third species of life alone, that of appetency. But Aristotle, while he thinks that plants are possessed of a life of vegetation and nutrition, does not consider it proper to call them animals; for that alone, which possesses the other life - that of sensation - he considers warrantable to be called an animal. The Stoics do not call the power of vegetation, life.

(1) Now every single class of living thing, Asclepius, of whatsoever kind, or it be mortal or be rational, whether it be endowed with soul, or be without one, just as each has its class, so does each several [class] have images of its own class. And though each separate class of animal has in it every form of its own class, still in the selfsame [kind of] form the units differ from each other. And so although the class of men is of one kind, so that a man can be distinguished by his [general] look, still individual men within the sameness of their [common] form do differ from each other.

(14) But the question was, whether the embryo is already an animal, or still a plant. And then the name animal was reduced to definition, for the sake of perspicuity. But having discovered that it is distinguished from what is not an animal by sensation and motion from appetency; we again separated this from its adjuncts; asserting that it was one thing for that to be such potentially, which is not yet possessed of the power of sensation and motion, but will some time be so, and another thing to be already so actually; and in the case of such, it is one thing to exert its powers, another to be able to exert them, but to be at rest or asleep. And this is the question.

(11) For of objects that are moved, some are moved by impulse and appearance, as animals; and some by transposition, as inanimate objects. And of things without life, plants, they say, are moved by transposition in order to growth, if we will concede to them that plants are without life. To stones, then, belongs a permanent state. Plants have a nature; and the irrational animals possess impulse and perception, and likewise the two characteristics already specified.

(16) Now one Division divides that which is divided into species, as a genus; and another into parts, as a whole; and another into accidents.

(11) All things incorporeal when in a body are subject unto passion, and in the proper sense they are [themselves] all passions. For every thing that moves itself is incorporeal; while every thing that's moved is body. Incorporeals are further moved by Mind, and movement's passion. Both, then, are subject unto passion - both mover and the moved, the former being ruler and the latter ruled. But when a man hath freed himself from body, then is he also freed from passion. But, more precisely, son, naught is impassible, but all are passible. Yet passion differeth from passibility; for that the one is active, while the other's passive. Incorporeals moreover act upon themselves, for either they are motionless or they are moved; but whichsoe'er it be, it's passion. But bodies are invaribly acted on, and therefore they are passible. Do not, then, let terms trouble thee; action and passion are both the selfsame thing. To use the fairer sounding term, however, does no harm.