The Essays of Adam Smith: THE HISTORY OF THE ANCIENT LOGICS AND METAPHYSICS

The Essays of Adam Smith, by Adam Smith is part of HackerNoon’s Book Blog Post series. You can jump to any chapter in this book here. THE PRINCIPLES WHICH LEAD AND DIRECT PHILOSOPHICAL ENQUIRIES; ILLUSTRATED BY THE HISTORY OF THEANCIENT LOGICS AND METAPHYSICS.

IN every transmutation, either of one element into another, or of one compound body either into the elements out of which it was composed, or into another compound body, it seemed evident, that both in the old and in the new species, there was something that was the same, and something that was different. When Fire was changed into Air, or Water into Earth, the Stuff, or Subject-matter of this Air and this Earth, was evidently the same with that of the former Fire or Water; but the Nature or Species of those new bodies was entirely different.

When, in the same manner, a number of fresh, green, and odoriferous flowers were thrown together in a heap, they, in a short time, entirely changed their nature, became putrid and loathsome, and dissolved into a confused mass of ordure, which bore no resemblance, either in sensible qualities or in its effects, to their former beautiful appearance. But how different soever the species, the subject-matter of the flowers, and of the ordure, was, in this case too, evidently the same. In every body therefore, whether simple or mixed, there were evidently two principles, whose combination constituted the whole nature of that particular body.

The first was the Stuff, or Subject-matter, out of which it was made; the second was the Species, the Specific Essence, the Essential, or, as the schoolmen have called it, the Substantial Form of the Body. 396 The first seemed to be the same in all bodies, and to have neither qualities nor powers of any kind, but to be altogether inert and imperceptible by any of the senses, till it was qualified and rendered sensible by its union with some species or essential form.

All the qualities and powers of bodies seemed to depend upon their species or essential forms. It was not the stuff or matter of Fire, or Air, or Earth, or Water, which enabled those elements to produce their several effects, but that essential form which was peculiar to each of them. For it seemed evident that Fire must produce the effects of Fire, by that which rendered it Fire; Air, by that which rendered it Air; and that in the same manner all other simple and mixed bodies must produce their several effects, by that which constituted them such or such bodies; that is, by their Specific Essence or essential forms. But it is from the effects of bodies upon one another, that all the changes and revolutions in the material world arise.

Since these, therefore, depend upon the specific essences of those bodies, it must be the business of philosophy, that science which endeavours to connect together all the different changes that occur in the world, to determine wherein the Specific Essence of each object consists, in order to foresee what changes or revolutions may be expected from it. But the Specific Essence of each individual object is not that which is peculiar to it as an individual, but that which is common to it, with all other objects of the same kind.

Thus the Specific Essence of the Water, which now stands before me, does not consist in its being heated by the Fire, or cooled by the Air, in such a particular degree; in its being contained in a vessel of such a form, or of such dimensions. These are all accidental circumstances, which are altogether extraneous to its general nature, and upon which none of its effects as Water depend. Philosophy, therefore, in considering the general nature of Water, takes no notice of those particularities which are peculiar to this water, but confines itself to those things which are common to all Water.

If, in the progress of its inquiries, it should descend to consider the nature of Water that is modified by such particular accidents, it still would not confine its consideration to this water contained in this vessel, and thus heated at this fire, but would extend its views to Water in general contained in such kind of vessels, and heated to such a degree at such a fire. In every case, therefore, Species, or Universals, and not Individuals, are the objects of Philosophy. Because whatever effects are produced by individuals, whatever changes can flow from them, must all proceed from some universal nature that is contained in them.

As it was the business of Physics, or Natural Philosophy, to determine wherein consisted the Nature and Essence of every particular Species of things, in order to connect together all the different events that occur in the material world; so there were two other sciences, which, though they had originally arisen out of that system of Natural Philosophy I have just  been describing, were, however, apprehended to go before it, in the order in which the knowledge of Nature ought to be communicated.

The first of these, Metaphysics, considered the general nature of Universals, and the different sorts or species into which they might be divided. The second of these, Logics, was built upon this doctrine of Metaphysics; and from the general nature of Universals, and of the sorts into which they were divided, endeavoured to ascertain the general rules by which we might distribute all particular objects into general classes, and determine to what class each individual object belonged; for in this, they justly enough apprehended, consisted the whole art of philosophical reasoning.

As the first of these two sciences, Metaphysics, is altogether subordinate to the second, Logic, they seem, before the time of Aristotle, to have been regarded as one, and to have made up between them that ancient Dialectic of which we hear so much, and of which we understand so little: neither does this separation seem to have been much attended to, either by his own followers, the ancient Peripatetics, or by any other of the old sects of philosophers. The later schoolmen, indeed, have distinguished between Ontology and Logic; but their Ontology contains but a small part of what is the subject of the metaphysical books of Aristotle, the greater part of which, the doctrines of Universals, and everything that is preparatory to the arts of defining and dividing, has, since the days of Porphery, been inserted into their Logic.

According to Plato and Timæus, the principles out of which the Deity formed the World, and which were themselves eternal, were three in number. The Subject-matter of things, the Species, or Specific Essences of things, and what was made out of these, the sensible objects themselves. These last had no proper or durable existence, but were in perpetual flux and succession. For as Heraclitus had said that no man ever passed the same river twice, because the water which he had passed over once was gone before he could pass over it a second time; so, in the same manner, no man ever saw, or heard, or touched the same sensible object twice. When I look at the window, for example, the visible species, which strikes my eyes this moment, though resembling, is different from that which struck my eyes the immediately preceding moment. When I ring the bell, the sound, or audible species, which I hear this moment, though resembling in the same manner, is different, however, from that which I heard the moment before.

When I lay my hand on the table, the tangible species which I feel this moment, though resembling, in the same manner, is numerically different too from that which I felt the moment before. Our sensations, therefore, never properly exist or endure one moment; but, in the very instant of their generation, perish and are annihilated for ever. Nor are the causes of those sensations more permanent. No corporeal substance is ever exactly the  same, either in whole or in any assignable part, during two successive, moments, but by the perpetual addition of new parts, as well as loss of old ones, is in continual flux and succession. Things of so fleeting a nature can never be the objects of science, or of any steady or permanent judgment. While we look at them, in order to consider them, they are changed and gone, and annihilated for ever.

The objects of science, and of all the steady judgments of the understanding, must be permanent, unchangeable, always existent, and liable neither to generation nor corruption, nor alteration of any kind. Such are the species or specific essences of things.

Man is perpetually changing every particle of his body; and every thought of his mind is in continual flux and succession. But humanity, or human nature, is always existent, is always the same, is never generated, and is never corrupted.

This, therefore, is the object of science, reason, and understanding, as man is the object of sense, and of those inconstant opinions which are founded upon sense. As the objects of sense were apprehended to have an external existence, independent of the act of sensation, so these objects of the understanding were much more supposed to have an external existence independent of the act of understanding. Those external essences were, according to Plato, the exemplars, according to which the Deity formed the world, and all the sensible objects that are in it. The Deity comprehended within his infinite essence, all these species, or external exemplars, in the same manner as he comprehended all sensible objects.

Plato, however, seems to have regarded the first of those as equally distinct with the second from what we would now call the Ideas or Thoughts of the Divine Mind, and even to have supposed, that they had a particular place of existence, beyond the sphere of the visible  corporeal world; though this has been much controverted, both by the later Platonists, and by some very judicious modern critics, who have followed the interpretation of the later Platonists, as what did most  honour to the judgment of that renowned philosopher.

All the objects in this world, continued he, are particular and individual. Here, therefore, the human mind has no opportunity of seeing any Species, or Universal Nature. Whatever ideas it has, therefore, of such beings, for it plainly has them, it must derive from the memory of what it has seen, in some former period of its existence, when it had an opportunity of visiting the place or Sphere of Universals. For some time after it is immersed in the body, during its infancy, its childhood, and a great part of its youth, the violence of those passions which it derives from the body, and which are all directed to the particular and individual objects of this world, hinder it from turning its attention to those Universal Natures, with which it had been conversant in the world from whence it came.

The Ideas, of these, therefore, seem, in this first period of its existence here, to be overwhelmed in the confusion of those turbulent emotions, and to be almost entirely wiped out of its remembrance. During the continuance of this state, it is incapable of Reasoning, Science and Philosophy, which are conversant about Universals. Its whole attention is turned towards particular objects, concerning which, being directed by no general notions, it forms many vain and false opinions, and is filled with error, perplexity, and confusion. But, when age has abated the violence of its passions, and composed the confusion of its thoughts, it then becomes more capable of reflection, and of turning its attention to those almost forgotten ideas of things with which it had been conversant in the former state of its existence. All the particular objects in this sensible world, being formed after the eternal exemplars in that intellectual world, awaken, upon account of their resemblance, insensibly, and by slow degrees, the almost obliterated ideas of these last.

The beauty, which is shared in different degrees among terrestrial objects, revives the same idea of that Universal Nature of beauty which exists in the intellectual world: particular acts of justice, of the universal nature of justice; particular reasonings, and particular sciences, of the universal nature of science and reasoning; particular roundnesses, of the universal nature of roundness; particular squares, of the universal nature of squareness.

Thus science, which is conversant about Universals, is derived from memory; and to instruct any person concerning the general nature of any subject, is no more than to awaken in him the remembrance of what he formerly knew about it. This both Plato and Socrates imagined they could still further confirm, by the fallacious experiment,  which showed, that a person might be led to discover himself, without any information, any general truth, of which he was before ignorant, merely by being asked a number of properly arranged and connected questions concerning it.

He calls them, indeed, Ideas, a word which, in him, in Aristotle, and all the other writers of earlier antiquity, signifies a Species, and is perfectly synonymous with that other word Ειδος, more frequently made use of by Aristotle. As, by some of the later sects of philosophers, particularly by the Stoics, all species, or specific essences, were regarded as mere creatures of the mind, formed by abstraction, which had no real existence external to the thoughts that conceived them, the word Idea came, by degrees, to its present signification, to mean, first, an abstract thought or conception; and afterwards, a thought or conception of any kind; and thus became synonymous with that other Greek word, Εννοια, from which it had originally a very different meaning.

When the later Platonists, who lived at a time when the notion of the separate existence of specific essences was universally exploded, began to comment upon the writings of Plato, and upon that strange fancy that, in his writings, there was a double doctrine; and that they were intended to seem to mean one thing, while at bottom they meant a very different, which the writings of no man in his senses ever were, or ever could be intended to do; they represented his doctrine as meaning no more, than that the Deity formed the world after what we would now call an Idea, or plan conceived in his own mind, in the same manner as any other artist.

But, if Plato had meant to express no more than this most natural and simple of all notions, he might surely have expressed it more plainly, and would hardly, one would think, have talked of it with so much emphasis, as of something which it required the utmost reach of thought to comprehend. According to this representation, Plato’s notion of Species, or Universals, was the same with that of Aristotle.

Aristotle, however, does not seem to understand it as such; he bestows a great part of his Metaphysics upon confuting it, and opposes it in all his other works; nor does he, in any one of them, give the least hint, or insinuation, as if it could be suspected that, by the Ideas of Plato, was meant the thoughts or conceptions of the Divine Mind. Is it possible that he, who was twenty years in his school, should, during all that time, have misunderstood him, especially when his meaning was so very plain and obvious? Neither is this notion of the separate existence of Species, distinct both from the mind which conceives them, and from the sensible objects which are made to resemble them, one of those doctrines which Plato would but seldom have occasion to talk of.

However it may be interpreted, it is the very basis of his philosophy; neither is there a single dialogue in all his works which does not refer to it. Shall we suppose, that that great philosopher, who appears to have been so much superior to his master in every thing but eloquence, wilfully, and upon all occasions, misrepresented, not one of the deep and mysterious doctrines of the philosophy of Plato, but the first and most fundamental principle of all his reasonings; when the writings of Plato were in the hands of every body; when his followers and disciples were spread all over Greece; when almost every Athenian of distinction, that was nearly of the same age with Aristotle, must have been bred in his school; when Speusippus, the nephew and successor of Plato, as well as Xenocrates, who continued the school in the Academy, at the same time that Aristotle held his in the Lyceum, must have been ready, at all times, to expose and affront him for such gross disingenuity.

Does not Cicero, does not Seneca understand this doctrine in the same manner as Aristotle has represented it? Is there any author in all antiquity who seems to understand it otherwise, earlier than Plutarch, an author who seems to have been as bad a critic in philosophy as in history, and to have taken every thing at second-hand in both, and who lived after the origin of that eclectic philosophy, from whence the later Platonists arose, and who seems himself to have been one of that sect? Is there any one passage in any Greek author, near the time of Aristotle and Plato, in which the word Idea is used in its present meaning, to signify a thought or conception? Are not the words, which in all languages express reality or existence, directly opposed to those which express thought, or conception only? Or, is there any other difference betwixt a thing that exists, and a thing that does not exist, except this, that the one is a mere conception, and that the other is something more than a conception?

With what propriety, therefore, could Plato talk of those eternal species, as of the only things which had any real existence, if they were no more than the conceptions of the Divine Mind? Had not the Deity, according to Plato, as well as according to the Stoics, from all eternity, the idea of every individual, as well as of every species, and of the state in which every individual was to be, in each different instance of its existence? Were not all the divine ideas, therefore, of each individual, or of all the different states, which each individual was to be in during the course of its existence, equally eternal and unalterable with those of the species? With what sense, therefore, could Plato say, that the first were eternal, because the Deity had conceived them from all eternity, since he had conceived the others from all eternity too, and since his ideas of the Species could, in this respect, have no advantage of those of the individual?

Does not Plato, in many different places, talk of the Ideas of Species or Universals as innate, and having been impressed upon the mind in its state of pre-existence, when it had an opportunity of viewing these Species as they are in themselves, and not as they are expressed in their copies, or representatives upon earth? But if the only place of the existence of those Species was the Divine Mind, will not this suppose, that Plato either imagined, like Father Malbranche, that in its state of pre-existence, the mind saw all things in God: or that it was itself an emanation of the Divinity? That he maintained the first opinion, will not be pretended by any body who is at all versed in the history of science.

That enthusiastic notion, though it may seem to be favoured by some passages in the Fathers, was never, it is well known, coolly and literally maintained by any body before that Cartesian philosopher. That the human mind was itself an emanation of the Divine, though it was the doctrine of the Stoics, was by no means that of Plato; though, upon the notion of a pretended double doctrine, the contrary has lately been asserted.

According to Plato, the Deity formed the soul of the world out of that substance which is always the same, that is, out of Species or Universals; out of that which is always different, that is, out of corporeal substances; and out of a substance that was of a middle nature between these, which it is not easy to understand what he meant by. Out of a part of the same composition, he made those inferior intelligences who animated the celestial spheres, to whom he delivered the remaining part of it, to form from thence the souls of men and animals.

The souls of those inferior deities, though made out of a similar substance or composition, were not regarded as parts or emanations of that of the world; nor were those of animals, in the same manner, regarded as parts or emanations of those inferior deities: much less were any of them regarded as parts, or emanations of the great Author of all things.

The more the soul was accustomed to the consideration of those Universal Natures, the less it was attached to any particular and individual objects; it approached the nearer to the original perfection of its nature, from which, according to this philosophy, it had fallen. Philosophy, which accustoms it to consider the general Essence of things only, and to abstract from all their particular and sensible circumstances, was, upon this account, regarded as the great purifier of the soul.

As death separated the soul from the body, and from the bodily senses and passions, it restored it to that intellectual world, from whence it had originally descended, where no sensible Species called off its attention from those general Essences of things. Philosophy, in this life, habituating it to the same considerations, brings it, in some degree, to that state of happiness and perfection, to which death restores the souls of just men in a life to come.

Such was the doctrine of Plato concerning the Species or Specific Essence of things. This, at least, is what his words seem to import, and thus he is understood by Aristotle, the most intelligent and the most renowned of all his disciples. It is a doctrine, which, like many of the other doctrines of abstract Philosophy, is more coherent in the expression than in the idea; and which seems to have arisen, more from the nature of language, than from the nature of things.

With all its imperfections it was excusable, in the beginnings of philosophy, and is not a great deal more remote from the truth, than many others which have since been substituted in its room by some of the greatest pretenders to accuracy and precision. Mankind have had, at all times, a strong propensity to realize their own abstractions, of which we shall immediately see an example, in the notions of that very philosopher who first exposed the ill-grounded foundation of those Ideas, or Universals, of Plato and Timæus.

To explain the nature, and to account for the origin of general Ideas, is, even at this day, the greatest difficulty in abstract philosophy. How the human mind, when it reasons concerning the general nature of triangles, should either conceive, as Mr. Locke imagines it does, the idea of a triangle, which is neither obtusangular, nor rectangular, nor acutangular; but which was at once both none and of all those together; or should, as Malbranche thinks necessary for this purpose, comprehend at once, within its finite capacity, all possible triangles of all possible forms and dimensions, which are infinite in number, is a question, to which it is surely not easy to give a satisfactory answer.

Malbranche, to solve it, had recourse to the enthusiastic and unintelligible notion of the intimate union of the human mind with the divine, in whose infinite  essence the immensity of such species could alone be comprehended; and in which alone, therefore, all finite intelligences could have an opportunity of viewing them. If, after more than two thousand years reasoning about this subject, this ingenious and sublime philosopher was forced to have recourse to so strange a fancy, in order to explain it, can we wonder that Plato, in the very first dawnings of science, should, for the same purpose, adopt an hypothesis, which has been thought, without much reason, indeed, to have some affinity to that of Malbranche, and which is not more out of the way?

What seems to have misled those early philosophers, was, the notion, which appears, at first, natural enough, that those things, out of which any object is composed, must exist antecedent to that object. But the things out of which all particular objects seem to be composed, are the stuff or matter of those objects, and the form or specific Essence, which determines them to be of this or that class of things.

These, therefore, it was thought, must have existed antecedent to the object which was made up between them. Plato, who held, that the sensible world, which, according to him, is the world of individuals, was made in time, necessarily conceived, that both the universal matter, the object of spurious reason, and the specific essence, the object of proper reason and philosophy out of which it was composed, must have had a separate existence from all eternity. This intellectual world, very different from the intellectual world of Cudworth, though much of the language of the one has been borrowed from that of the other, was necessarily and always existent; whereas the sensible world owed its origin to the free will and bounty of its author.

A notion of this kind, as long as it is expressed in very general language; as long as it is not much rested upon, nor attempted to be very particularly and distinctly explained, passes easily enough, through the indolent imagination, accustomed to substitute words in the room of ideas; and if the words seem to hang easily together, requiring no great precision in the ideas. It vanishes, indeed; is discovered to be altogether incomprehensible, and eludes the grasp of the imagination, upon an attentive consideration. It requires, however, an attentive consideration; and if it had been as fortunate as many other opinions of the same kind, and about the same subject, it might, without examination, have continued to be the current philosophy for a century or two.

Aristotle, however, seems immediately to have discovered, that it was impossible to conceive, as actually existent, either that general matter, which was not determined by any particular species, or those species which were not embodied, if one may say so, in some particular portion of matter. Aristotle, too, held, as we have already observed the eternity of the sensible world. Though he held, therefore, that all sensible objects were made up of two principles, both of which, he calls, equally, substances, the matter and the specific essence, he was not obliged to hold, like Plato, that those principles existed prior in the order of time to the objects which they afterwards composed. They were prior, he said, in nature, but not in time, according to a distinction which was of use to him upon some other occasion. He distinguished, too, betwixt actual and potential existence.

By the first, he seems to have understood what is commonly meant by existence or reality; by the second, the bare possibility of existence. His meaning, I say, seems to amount to this; though he does not explain it precisely in this manner. Neither the material Essence of body could, according to him, exist actually without being determined by some Specific Essence, to some particular class of things, nor any Specific Essence without being embodied in some particular portion of matter.

Each of these two principles, however, could exist potentially in this separate state. That matter existed potentially, which, being endowed with a particular form, could be brought into actual existence; and that form, which, by being embodied in a particular portion of matter, could, in the same manner, be called forth into the class of complete realities. This potential existence of matter and form, he sometimes talks of, in expressions which resemble those of Plato, to whose notion of separate Essence it bears a very great affinity.

Aristotle, who seems in many things original, and who endeavoured to seem to be so in all things, added the principle of privation to those of matter and form, which he had derived from the ancient Pythagorean school. When Water is changed into Air, the transmutation is brought about by the material principle of those two elements being deprived of the form of Water, and then assuming the form of Air. Privation, therefore, was a third principle opposite to form, which entered into the generation of every Species, which was always from some other Species. It was a principle of generation, but not of composition, as is most obvious.

The Stoics, whose opinions were, in all the different parts of philosophy, either the same with, or very nearly allied to those of Aristotle and Plato, though often disguised in very different language, held, that all things, even the elements themselves, were compounded of two principles, upon one of which depended all the active, and upon the other all the passive, powers of these bodies.

The last of these, they called Matter; the first, the Cause, by which they meant the very same thing which Aristotle and Plato understood, by their specific Essences. Matter, according to the Stoics, could have no existence separate from the cause or efficient principle which determined it to some particular class of things. Neither could the efficient principle exist separately from the material, in which it was always necessarily embodied.

Their opinion, therefore, so far coincided with that of the old Peripatetics. The efficient principle, they said, was the Deity. By which they meant, that it was a detached portion of the etherial and divine nature,  which penetrated all things, that constituted what Plato would have called the Specific Essence of each individual object; and so far their opinion coincides pretty nearly with that of the latter Platonists, who held, that the Specific Essences of all things were detached portions of their created deity, the soul of the world; and with that of some of the Arabian and Scholastic Commentators of Aristotle, who held that the substantial forms of all things descended from those Divine Essences which animated the Celestial Spheres. Such was the doctrine of the four principal Sects of the ancient Philosophers, concerning the Specific Essences of things, of the old Pythagoreans, of the Academical, the Peripatetic, and the Stoical Sects.

As this doctrine of Specific Essences seems naturally enough to have arisen from that ancient system of Physics, which I have above described, and which is, by no means, devoid of probability, so many of the doctrines of that system, which seems to us, who have been long accustomed to another, the most incomprehensible, necessarily flow from this metaphysical notion. Such are those of generation, corruption, and alteration; of mixture, condensation, and rarefaction. A body was generated or corrupted, when it changed its Specific Essence, and passed from one denomination to another. It was altered when it changed only some of its qualities, but still retained the same Specific Essence, and the same denomination.

Thus, when a flower was withered, it was not corrupted; though some of its qualities were changed, it still retained the Specific Essence, and therefore justly passed under the denomination of a flower. But, when, in the further progress of its decay, it crumbled into earth, it was corrupted; it lost the Specific Essence, or substantial form of the flower, and assumed that of the earth, and therefore justly changed its denomination.

The Specific Essence, or universal nature that was lodged in each particular class of bodies, was not itself the object of any of our senses, but could be perceived only by the understanding. It was by the sensible qualities, however, that we judged of the Specific Essence of each object. Some of these sensible qualities, therefore, we regarded as essential, or such as showed, by their presence or absence, the presence or absence of that essential form from which they necessarily flowed. Others were accidental, or such whose presence or absence had no such necessary consequences. The first of these two sorts of qualities was called Properties; the second, Accidents.

In the Specific Essence of each object itself, they distinguished two parts; one of which was peculiar and characteristical of the one class of things of which that particular object was an individual, the other was common to it with some other higher classes of things. These two parts were, to the Specific Essence, pretty much what the Matter and the Specific Essence were to each individual body.

The one, which was called the Genus, was modified and determined by the other,  which was called the Specific Difference, pretty much in the same manner as the universal matter contained in each body was modified and determined by the Specific Essence of that particular class of bodies. These four, with the Specific Essence or Species itself, made up the number of the Five Universals, so well known in the schools by the names of Genus, Species, Differentia, Proprium, and Accidens.

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