90. The chief perfections of being are simplicity, infinity. necessity, and immutability.
I. Simplicity is that perfection which makes a being identical with everything that constitutes it; it is a positive perfection, but it is conceived by us in a negative way, viz.: by the exclusion of all composition. A being is absolutely simple if it excludes all manner of composition.
91. Composition implies a want of identity among the parts of a whole or unit. The whole and its divisions are called actual, if there is outside of the mind a true junction or combination of parts. If the parts can exist separately, e.g., 'soul' and 'body,' the actual unit is called physical: if they cannot, it is metaphysical. Thus man's 'animality' and 'rationality' are metaphysical parts of a metaphysical whole, for they cannot exist separately; take away from a man the principle of his rationality, the soul, and you have left, not an animal, but a dead body. It will be noticed the metaphysical division regards the comprehension of an idea. The whole and the division are called potential when the parts are not united outside the mind, but are capable of being classed together as realizing the same idea. For instance, 'animal' expresses a potential whole if we consider its extension -- i.e., the class of individuals to which it is applicable. This is often called the whole of extension, and also a logical whole, because the union of the individuals is not in nature but in the mind only, which apprehends them all by their common nature, and forms of them a mental unit. The latter division is the one which logic properly deals with; for it breaks up larger classes into smaller, and these into smaller again.
92. II. The Infinite is the perfection which contains all entity so that none be wanting; it is a most positive perfection, though conceived in a negative way, viz.: by denying all limitation. But, since limitation is itself a negation of further perfection, the absence of limitation in a being, i.e., its infinity, is a negation of a negation, and therefore an affirmation.
The Potential Infinite is the finite conceived as capable of constant increase; it is, therefore, not truly infinite but indefinite, though in mathematics it is usually called infinite. The infinite cannot be measured or counted; because measure and number express a limit, and the infinite has no limit. It is also to be observed that no amount of finite additions can ever make the finite become infinite.
93. Thesis IX. No existing quantity can be infinite.
Proof. Since the essence of quantity implies divisibility, any existing quantity may be divided, at least mentally. Let us, then, cut off a small portion from the quantity which was supposed to be infinite; what remains will be finite; and that finite remainder increased by the small portion cut off will be infinite. But this is absurd, viz., that a finite quantity should differ from the infinite by a small portion. Besides, suppose we add to the finite remainder a portion greater than that cut off; we should then have a quantity greater than infinite, which is impossible. An infinite body would measure an infinite number of yards, and more than an infinite number of feet.
94. Objections: 1. The multitude of possibles is infinite; for there is no limit to the things that God can create. Answer. The possibles are not existing; the thesis regards existing quantity.
2. The acts of creatures will go on increasing in multitude for ever. Answer. The number of past acts will always be actually finite, though capable of constant increase -- i.e., the multitude of future acts is indefinite.
3. It cannot be indefinite; for God knows all future acts of His creatures distinctly, and therefore definitely. Answer. God's knowledge is conformable to the reality -- i.e., to the object of that knowledge; now, that object is a series of acts, all distinct from one another, ever continuing, but never being an existing infinite series. Besides, distinctness of knowledge is opposed to vagueness of knowledge, and need not imply limitation of the things known.
4. Any extended body contains an infinite multitude of parts. Answer. The number of ultimate particles into which a body can physically be divided is finite; but the extension of the body can be mathematically divided without end -- i.e., it is potentially, not really, infinite in its divisibility.
95. It may be asked how we acquire the idea of the infinite. We do so, not by intuition of the Infinite Being, or God, nor by mentally adding perfections to perfections, for finite things added together can never give the infinite; but seeing finite things we distinguish in them, by abstraction, perfection and limitation; next, by denying limitation we form the abstract concept of unlimited perfection, i.e., of the Infinite Being. The idea thus formed is of a positive object; objectively considered, it is not negative, but most positive; but subjectively considered, it implies affirmation and negation. The idea of the finite, on the other hand, is not a mere negation; for it is the affirmation of something and no more -- i.e., it affirms one thing and denies anything beyond.
96. III. A necessary being is one whose non-existence is impossible. It is hypothetically necessary, if its non-existence is impossible under a certain hypothesis or supposition; it is absolutely necessary, if its non-existence is impossible under any supposition. Now, this cannot be the case unless its very nature implies existence, unless the being be self-existent. If such a being exists it must have always existed, and cannot cease to exist, else its non-existence would not be absolutely impossible; it is therefore eternal -- i.e., without beginning and without end.
97. Any being which is not absolutely necessary is said to be contingent -- i.e., it may be or not be, it is not self-existing. If it exists and yet has not in itself the reason of its existence, it must then have that reason in another being; but to have the reason of one's existence in another is to have a cause; therefore every contingent being, if it exists, must have a cause.
98. IV. Immutability is the necessity of remaining the selfsame, the impossibility of changing. A change is a transition from one state of being to another. It implies three things: (a) A former state which is abandoned. (b) A latter state which is assumed. (c) A subject that abandons the one state and assumes the other.
99. The change may occur variously: 1. A substance may be changed from one species to another by losing an old and acquiring a new substantial form, as when metals are oxidized. 2. The subject may acquire or lose some substance without change of its species, as when a sand-bank grows larger or smaller. 3. It may acquire or lose a quality, as when iron gets hot or cold. 4. It may pass from local motion to rest, or from rest to local motion. 5. It may assume a new arrangement of parts, as when water freezes. 6. Supernaturally, one substance may be substituted for another while the accidents remain, as when the bread and wine are changed into the body and blood of Christ. But in this case the word change is taken analogically for transubstantiation. A change of relation between one being and another is called an extrinsic change. This may occur though one of the two beings remains absolutely immutable, as when God became a Creator without undergoing any intrinsic change, simply because the creatures began to exist, and thus a new relation was established toward God which had not existed before.