might well be a reminiscence of the great massacre at the Colline gate.

¹⁴   Cp. Munro, Note II, p. 413. Third Edition.

¹⁵   'Si jam violentior aliqua in re C. Caesar fuisset, si eum magnitudo contentionis, studium gloriae, praestans animus, excellens nobilitas aliquo impulisset.'—In Vatinium 6.

¹⁶   iv. 973, etc.

¹⁷   iv. 75, etc.

¹⁸   ii. 24, etc.

¹⁹   In places where he is not drawing from his own observation, he uses such expressions as memorant; e.g. iii. 642.

²⁰   E.g. iv. 353, etc.

²¹   E.g.

and

²²   Obermann, by M. Arnold.

²³   i. 935-50.

²⁴   'And can discourse much on the combination of things, and enquire moreover, what are their own first elements.'

²⁵   'While I seem ever to be plying this task earnestly, to be enquiring into Nature, and explaining my discoveries in writings in my native tongue.' This is one of those passages which seem to indicate an unhealthy overstrain which may have been the precursor of the final disturbance of 'his power to shape.'

²⁶   Cp. Munro's notes on the passages where these expressions occur.

²⁷   E.g. ii. 77, etc. Augescunt aliae gentes, etc., suggested by a passage in the Laws:— γεννῶντάς τε καὶ ἐκτρέφοντας παῖδας, καθάπερ λαμπάδα τὸν βίον παραδιδόντας ἄλλοις ἐξ ἄλλων —and the lines which recur several times, etc. 'Nam veluti pueri trepidant,' which Mr. Munro aptly compares with the words in the Phaedo (77), ἴσως ἔνι τις καὶ ἐν ἡμῖν παῖς, ὅστις τὰ τοιαῦτα φοβεῖται.

²⁸   v. 8.

²⁹   Cf.

³⁰   'But nought greater than this man does it seem to have possessed, nor aught more holy, more wonderful, or more beloved. Yea, too, strains of divine genius proclaim aloud and make known his great discoveries, so that he seems scarcely to be of mortal race.'—i. 729-33.

³¹   'When they have gazed for a few years of a life that is indeed no life, speedily fulfilling their doom, they vanish away like a smoke, convinced of that only which each hath met in his own experience, as they were buffeted about to and fro. Vainly doth each boast to have discovered the whole. The eye cannot behold it, nor the ear hear it, nor the mind of man comprehend it.'

³²   'With death there is ever blending the wail of infants newly born into the light. And no night hath ever followed day, no morning dawned on night, but hath heard the mingled sounds of feeble infant wailings and of lamentations that follow the dead and black funeral train.'—ii. 576-80.

³³   i. 943-50.

³⁴   iii. 1036-38.

³⁵   Cf. notes ii. of Mr. Munro's edition.

³⁶   i. 117, etc.

³⁷   Mr. Froude, in his 'Julius Caesar,' says, 'The age was saturated with cant.' Perhaps, to that condition of the age we, in part, owe one of the sincerest protests against cant, and unreality of every kind, ever written. Both speculatively and practically Cicero appears at a great disadvantage when compared with Lucretius in these respects.

CHAPTER XII.

The Philosophy of Lucretius.

The peculiarity of the poem of Lucretius, that which makes it unique in literature, is the fact that it is a long sustained argument in verse. The prosaic title of the poem, 'De rerum natura,'—a translation of the Greek περὶ φύσεως,—indicates that the method of exposition was adopted, not primarily with the view of affecting the imagination, but with that of communicating truth in a reasoned system. In the lines, in which the poet most confidently asserts his genius, he professes to fulfil the three distinct offices of a philosophical teacher, a moral reformer, and a poet,—

We have, accordingly, to examine the poem in three different aspects:—

I. as the exposition of a system of speculative philosophy.

II. as an attempt to emancipate and reform human life.

III. as a work of poetical art and genius.

But these three aspects, though they may be considered separately, are not really independent of one another. The speculative ideas on which the system of philosophy is ultimately based impart confidence and elevation to the moral teaching, and new meaning and imaginative grandeur to the interpretation of Nature and of human life, on which the permanent value of the poem depends. Thus, although the philosophical argument, which forms as it were the skeleton of the work, is in many places barren and uninteresting, yet it is necessary to master it before we can form a true estimate of the personality of the poet, of the main passion and labour of his life, of the full meaning of his thought, and the full compass of his poetic genius. Moreover, the study of the argument is interesting on its own account. In no other work are the strength and the weakness of ancient physical philosophy so apparent. If the poem of Lucretius adds nothing to the knowledge of scientific facts, it throws a powerful light on one phase of the ancient mind. It is a witness of the eager imagination and of the searching thought of that early time, which endeavoured, by the force of individual thinkers and the intuitions of genius, to solve a problem which is perhaps beyond the reach of the human faculties, and to explain, at a single glance, secrets of Nature which have only slowly been revealed to the patient labours and combined investigations of many generations of enquirers.

I.—Examination of the Argument.

I.  The philosophical system expounded in the poem is the atomic theory of Democritus², in the form in which it was accepted by Epicurus, and made the basis of his moral and religious doctrines. Lucretius lays no claim to original discovery as a philosopher: he professes only to explain, in his native language, 'Graiorum obscura reperta.' His originality consists, not in any expansion or modification of the Epicurean doctrine, but in the new life which he has imparted to its exposition, and in the poetical power with which he has applied it to reveal the secret of the life of Nature and of man's true position in the world. After enunciating the first principles of the atomic philosophy, he discusses in the last four books of the poem some special applications of that doctrine, which formed part of the physical system of Epicurus. But the extent to which he carries these discussions is limited by the practical purpose which he has in view. The impelling motive of all his labour is the impulse to purify human life, and, especially, to emancipate it from the terrors of superstition. The source of these terrors is traced to the general ignorance of certain facts in Nature,—ignorance, namely, of the constitution and condition of our souls and bodies, of the means by which the world came into existence and is still maintained, and lastly, of the causes of many natural phenomena, which are attributed to the direct agency of the gods. With the view of establishing knowledge in the room of ignorance on these questions, it is necessary, in the first place, to give a full account of the original principles of being: and to this enquiry the two first books of the poem are devoted. Had his purpose been merely speculative, the subject of the fifth book,—viz. the origin of the world, of life, and of human society,—would naturally have been treated immediately after the exposition of these first principles. But the order of treatment is determined by the immediate object of attacking the chief stronghold of superstition: and, accordingly, the third and fourth books contain an examination of the nature of the soul, a proof of its non-existence after death, and an explanation of the origin of the belief in a future state. In the fifth and sixth books an attempt is made to show that the creation and preservation of the world, the origin and progress of human society, and the phenomena of thunder, tempests, volcanoes, and the like, are the results of natural laws, without Divine intervention. Although he sometimes carries his argument into greater detail than is necessary for his purpose, and addresses himself to the reform of other evils to which the human heart is liable, yet his whole treatment of his subject is determined by the thought of the irreconcilable opposition between the truths of Nature and the falsehood of the ancient religions. The key-note to the argument is contained in the lines, which recur as a kind of prelude to the successive stages on which it enters, in the first, second, third, and sixth books:—

The action of the poem might be described as the gradual defeat of the ancient dominion of superstition by the new knowledge of Nature. This meaning seems to be symbolised in its magnificent introduction, where the genial, all-pervading Power—the source of order, beauty, and delight in the world and in the heart of man,—and the grim phantom of superstition—

the cause of ignorance, degradation, and misery,—are vividly personified and presented in close contrast with one another. The thought, thus symbolised, pervades the poem. The processes of Nature are explained not chiefly for the purpose of satisfying the love of knowledge (although this end is incidentally attained), but as the means of establishing light in the room of darkness, peace in the room of terror, faith in the laws and the facts of the universe in the room of a base dependence on capricious and tyrannical Powers.

What then was this philosophy which supplied to Lucretius an answer to the perplexities of existence? The object contemplated by all the early systems of ontology was the discovery of the original substance or substances out of which all existing things were created, and which alone remained permanent amid the changing aspects of the visible world. Various systems, of a semi-physical, semi-metaphysical character, were founded on the answers given by the earliest enquirers to this question. In the first book of the poem several of these theories are discussed. Lucretius, following Epicurus, adopts the answer given by Democritus to this question, that the original substances were the 'atoms and the void'— ἄτομα καὶ κενόν. After the invocation and the address to Memmius, and the representation of the universal tyranny exercised by superstition until its power was overcome by Epicurus, and after a summary of the various topics to be treated in order to banish this influence from the world, he lays down this principle as the starting-point of his argument,—that no existing thing is formed out of nothing by divine agency—

The apprehension of this principle—a principle common to all the ontological systems of antiquity—is the first step in the enquiry, as to what are the original substances out of which all creation comes into being and is maintained. The proof of this principle is the manifest order and causation recognisable in the world. If things could arise out of nothing, all existence would be confused and capricious. The regularity of Nature subsists—

The complement of this first principle is the proposition that nothing is annihilated, but all existences are resolved into their ultimate elements. As the first is a necessary inference from the existence of universal order, the second is proved by the perpetuity of creation and the observed transformation of things into one another.

The original substances out of which all things are produced, and into which they are ultimately resolved, are found to be certain primordial particles of matter or atoms, which are called by various names—'materies,' 'genitalia corpora,' 'semina rerum,' 'corpora prima.' Some of these names, it may be observed, are expressive not only of their primordial character, but also of a germinative or productive power. The objection that these atoms are invisible to our senses is met by showing that there are many invisible forces acting in Nature, the effects of which prove that they must be bodies,—

In addition to bodily substance there must also be vacuum or space; otherwise there could be no motion in the universe, and without motion nothing could come into being. The existence of matter is proved by our senses, of vacuum by the necessity of there being space for matter to move in, and also by the varying density of bodies. But besides body and vacuum there is no other absolute substance—

All material bodies are either elemental substances or compounded out of a union of these substances. The elemental substances are indestructible and indivisible. This is proved by the necessities of thought (i. 498, etc.) and of Nature. If there were no ultimate limit to the divisibility of these substances, if there were not something immutable underlying all phenomena, there could be no law or order in the world. The existence and ultimate constitution of the atoms is thus enunciated—

At this stage in the argument, from line 635 to 920 of Book I, the first principles of other philosophies, and particularly of the systems of Heraclitus, Empedocles, and Anaxagoras, are discussed at considerable length, and shown to be inconsistent with the actual appearance of things and with the principles already established.

The argument starts anew at line 920, and it is shown that the atoms must be infinite in number, and space infinite in extent;—the contrary supposition being both inconceivable and incompatible with the origin, preservation, and renewal of all existing things. It is shown also that the existing order of things has not come into being through design, but by infinite experiments through infinite time. The doctrine that all things tend to a centre is denied, and the book concludes with the imaginative presentation of the thought that, if matter were not infinite, the whole visible fabric of the world would perish in a moment, 'and leave not a rack behind.'

The second book opens with an impressive passage, in which the security and charm of the contemplative life is contrasted with the restless anxieties and alarms of the life of worldly ambition. The argument then proceeds to explain the process by which these atoms, primordial, indestructible, and infinite in number, combine together in infinite space, so as to carry on the birth, growth, and decay of all things. While the sum of things always remains the same, there is constant change in all phenomena. This is explicable only on the supposition of the original elements being in eternal motion. The atoms are borne through space, either by their own weight, or by contact with one another, with a rapidity of motion far beyond that of any visible bodies. All motion is naturally in a downward direction and in parallel lines, but to account for the contact of the atoms with one another it must be supposed that in their movements they make a slight declension from the straight line at uncertain intervals. This liability to declension is the sole thing to break the chain of necessity—'quod fati foedera rumpat.' It is through this liability in the primal elements that volition in living beings becomes possible.

As the sum of matter in the universe is constant, so the motions of the atoms always have been and always will be the same⁶. All things are in ceaseless motion, although they may present to our senses the appearance of perfect rest.

It is necessary further to assume the existence of other properties in the atoms, in order to account for the variety in Nature, and the individuality of existing things. They have original differences in form; some are smooth, others round, others rough, others hooked, &c. These varieties in form are not infinite, but limited in number.

As the diversity in the world depends on the diversity of these forms, the order and regularity of Nature imply that there is a limit to these varieties. But while they are limited, the individuals of each kind are infinite, otherwise the primordial atoms would be finite in number, and there could be no cohesion among atoms of the same kind, in the vast and chaotic sea of matter—

The motions which tend to the support and the destruction of created things are balanced by one another: there must be an equilibrium in these opposing forces—

Death and birth succeed one another, as now the vitalising, now the destructive forces gain the upper hand.

Further, the great diversity in Nature is to be accounted for by diversity, not only in the original forms of matter, but also in their modes of combination. No existing thing is composed solely of one kind of atoms. The greater the variety of forces and powers which anything displays, the greater is the variety of the elements out of which it was originally composed. Of all visible objects the earth contains the greatest number of elements; therefore it has justly obtained the name of the universal mother. There is however a limit to the modes in which atoms can combine with one another: each nature appropriates elements suitable to its being and rejects those unsuitable. All existing things differ from one another in consequence of the difference in their elements and in their modes of combination. The different modes of combination give rise to many of the secondary properties of matter, which are not in the original elements. Colour, for instance, is not one of the original properties of atoms: for all colour is changeable, and all change implies the death of what previously existed. Moreover, colour depends on light, and the atoms never come forth into the light. The atoms are also devoid of heat and cold, of sound, taste, and smell. All these properties must be kept distinct from the original elements—

Further, although they are the origin of all living and sentient things, the atoms themselves are devoid of sense and life, otherwise they would be liable to death. All living things are merely results of the constant changes in the primordial elements contained in the heavens and the earth. Hence the heaven is addressed as the father, the earth as the mother, of all things that have life.

Finally, from the infinity of space and matter, it may be inferred that there are infinite other worlds and systems beside our own. Many elements were added from the infinite universe to our system before it reached maturity: and many indications prove that the period of growth is now past, and that we are living in the old age of the world.

The sum of the first two books, in which the principles of the atomic philosophy are methodically unfolded and illustrated, is, accordingly, to this effect:—that all things have their origin in, and are sustained by, the various combinations and motions of solid elemental atoms, infinite in number, various in form, but not infinite in the variety of their forms,—not perceptible to our senses, and themselves devoid of sense, of colour, and of all the secondary properties of matter. These atoms, by virtue of their ultimate conditions, are capable only of certain combinations with one another. These combinations have been brought about by perpetual motion, through infinite space and through all eternity. As the order of things now existing has come into being, so it must one day perish. Only the atoms will permanently remain, moving unceasingly through space, and forming new combinations with one another.

These first principles being established, the way is made clear for the true explanation, according to natural laws, of those phenomena which give rise to and maintain the terrors of superstition.

The third book treats of the nature of the mind, and of the vital principle. As it is by the fear of death, and of eternal torment after death, that human life is most disturbed, it is necessary to explain the nature of the soul, and to show that it perishes in death along with the body.

The mind and the vital principle are parts of the man as much as the hands, feet, or any other members. The mind is the directing principle, seated in the centre of the breast. The vital principle is diffused over the whole body, obedient to and in close sympathy with the mind. The power which the mind has in moving the body proves its own corporeal nature, as motion cannot take place without touch, nor touch without the presence of a bodily substance.

The soul (including both the mind and vital principle) is, therefore, material, formed of the finest or minutest atoms, as is proved by the extreme rapidity of its movement, and by the fact that there is nothing lost in appearance or weight immediately after death:—

Four distinct elements enter into the composition of the soul—heat, wind, calm air, and a finer essence 'quasi anima animai.' The variety of disposition in men and animals depends on the proportion in which these elements are mixed.

The soul is the guardian of the body, inseparably united with it, as the odour is with frankincense; nor can the soul be disconnected from the body without its own destruction. This intimate union of soul and body is proved by many facts. They are born, they grow, and they decay together. The mind is liable to disease, like the body. Its affections are often dependent on bodily conditions. The difficulties of imagining the state of the soul as existing independently of the body are next urged; and the book concludes with a long passage of sustained elevation of feeling, in which the folly and the weakness of fearing death are passionately insisted upon.

The fourth book, which treats of the images which all objects cast off from themselves, and, in connexion with that subject, of the senses generally, and of the passion of love, is intimately connected with the preceding book. If there is no life after death, what is the origin of the universal belief in the existence of the souls of the departed? Images cast off from the surface of bodies, and borne incessantly through space without force or feeling, appearing to the living sometimes in sleep and sometimes in waking visions, have suggested the belief in the ghosts of the dead, and in many of the portents of ancient mythology. The rapid formation and motion of these images and their great number are explained by various analogies. Some apparent deceptions of the senses are next mentioned and explained. These deceptions are shown to be not in the senses, but in our minds not rightly interpreting their intimations. There is no error in the action of the senses. They are our 'prima fides'—the foundation of all knowledge and of all conduct—

Images that are too fine to act on the senses sometimes directly affect the soul itself. Discordant images unite together in the air, and present the appearance of Centaurs, Scyllas, and the like. In sleep, images of the dead—

appear, and give rise to the belief in the existence of ghosts. The mind sees in dreams the objects in which it is most interested, because, although all kinds of images are present, it can discern only those of which it is expectant.

Several other questions are discussed in connexion with the doctrine of the 'simulacra.' The final cause of the senses and the appetites is denied, and, by implication, the argument from design founded on the belief in final causes. The use of everything is discovered through experience. We do not receive the sense of sight in order that we may see, but having got the sense of sight, we use it—

There follows an account of sleep, and of the condition of the mind during that state; and the book concludes with a physical account of the passion of love, which is dependent on the action of the simulacra on the mind. Love is shown also to arise from natural causes, and not to be engendered by divine influence. The fatal consequences of yielding to the passion are then enforced with much poetical and satiric power.

The object of the fifth book is to explain the formation of our system—of earth, sea, sky, sun, and moon,—the origin of life upon the earth, and the advance of human nature from a savage state to the arts and usages of civilisation. The purpose of these discussions is to show that all our system was produced and is maintained by natural agency, that it is neither itself divine nor created by divine power, and that, as it has come into existence, so it must one day perish.

As the parts of our system,—earth, water, air, and heat,—are perishable, and constantly passing through processes of decay and renovation, the system must have had a beginning, and will have an end. There must at last be an end of the long war between the contending elements.

The world came into existence as the result not of design, but of every variety of combination in the elemental atoms throughout infinite time. Originally all were confused together. Gradually those that had mutual affinities combined and separated themselves from the rest. The earthy particles sank to the centre. The elemental particles of the empyrean (aether ignifer) formed the 'moenia mundi.' The sun and moon were formed out of the particles that were neither heavy enough to combine with the earth, nor light enough to ascend to the highest heaven. Finally, the liquid particles separated from the earth and formed the sea. Highest above all is the empyrean, entirely separated from the storms of the lower air, and moving round with its stars by its own impetus. The earth is at rest in the centre of our system, supported by the air, as our body is by the vital principle. The movements of the stars and of the sun and moon through the heavens are next explained; then the origin of vegetable and animal life on the earth, and the beginning and progress of human society.

First plants and trees, afterwards men and animals, were produced from the earth in the early and vigorous prime of the world. Many of the animals originally produced afterwards became extinct. Those only were capable of continuation which had either some faculty of self-preservation against others, or were useful to man, and so shared his protection. The existence of monsters such as Scylla, the Centaurs, the Chimaera, is shown to be impossible according to the natural laws of production.

The earliest condition of man was one of savage vigour and power of endurance, but liable to danger and destruction from many causes. The first humanising influence is traced to domestic union and the affection inspired by children—

The origin of language is next explained, then that of civil society, of religion, and of the arts,—the general conclusion being that all progress is the result of natural experience, not of divine guidance.

The last source of superstition is our ignorance of the causes of natural phenomena—

Hence the sixth book is devoted to the explanation of thunderstorms, tempests, volcanoes, earthquakes, and the like,—phenomena which are generally attributed to the direct agency of the gods. The whole work terminates with an account of the Plague at Athens, closely following that given by Thucydides.

The first question which arises after a review of the whole argument is that suggested by the statement of Jerome, and brought into prominence since the publication of Lachmann's edition of Lucretius, viz. whether there is good reason for believing that the poem was left by the author in an unfinished state. In answering this question, it is to be observed, on the one hand, that there is no incompleteness in the fulfilment of the original plan of the work, unless from one or two hints¹⁶ we conclude that the poet intended giving a fuller account of the blessed state of the Gods than that given at iii. 17-24. He announces at i. 54, etc., and again at i. 127, etc., the design of the poem as embracing the first principles of natural philosophy, and the application of these principles to certain special subjects, viz. the nature of soul and body, the origin of the belief in ghosts, the natural causes of creation, and the meaning of certain celestial phenomena.

The practical purpose of the poem—the overthrow of superstition—limits the argument to these subjects of discussion. They are severally mentioned where the argument is resumed in Books iii, iv, v, and vi, as those matters which require a clear explanation from the poet. All the topics enunciated in the opening statement are discussed with the utmost fulness. The great strongholds of superstition are attacked and overthrown in regular succession. In the introduction to the sixth book, the lines (91-95)

clearly show that the poet considered himself approaching the end of his task.

But, on the other hand, an examination of the poem in detail leads to the conclusion that it did not receive its author's final touch. The continuity of the argument is occasionally broken in all the books except the first. In the fourth, fifth, and sixth, especially, these breaks are very frequent, and there are more frequent instances in them of repetition and careless workmanship. They extend also to a greater length than the earlier books, which would naturally be the case if they had not received the author's final revision. The poem throughout gives the impression of great fulness of matter—

and in the composition of these later books, new suggestions seem to have been constantly occurring to the poet as new materials were added to his stores of knowledge: and the first draft of his argument has not been recast so as to incorporate and harmonise them with it. The passages containing these new materials appear to have been fitted into the place which they now occupy in the work, not always very judiciously, either by Cicero or some other editor.

It was also part of the author's design to enunciate his deepest thoughts on the Gods, on Nature, and on human life in more highly finished digressions from the main argument. Such passages are, in general, introduced at the beginning and the end of the different books. They seem to bring out the more catholic interest which underlies the special subject of the poem. Some of these passages are highly finished, and were evidently fixed by the poet in the places which he designed them to occupy. Such are, especially, the introductions to the first, second, and third books, and the concluding passages of the second and third. But the repetition of a passage of the first book as the introduction to the fourth, the long break in the continuity of the introduction to the fifth, the unfinished style of that to the sixth, and the abrupt and episodical conclusion to the whole poem (when contrasted with its elaborately artistic introduction), show that the same cause which marred the symmetry of his argument deprived it of the finished execution of a work of art. Yet these books—especially the fifth—are as rich in poetical feeling and substance as the earlier ones. The eye and hand of the master are as powerful as in the first enthusiasm with which he dedicated himself to his task, but they are less certain in their action. Whether his powers became intermittent owing to the attacks of illness, or whether his habit was to work roughly in the first instance and to perfect his work by subsequent revision, which in the case of his latest labours was prevented by death, must remain uncertain. It is a noticeable result of the vastness of the tasks which Roman genius set before itself, that two such works as the didactic poem of Lucretius and the Aeneid of Virgil were left unfinished by their authors, and given to the world in a more or less imperfect condition by other hands.

The poem, though incomplete in regard to the arrangement of its materials and artistic finish, presents a full and clear view of the philosophy accepted and expounded by Lucretius. What, then, is the intellectual interest and value of the work, considered as a great argument, in which the plan of Nature is explained, and the position of man in relation to that plan is determined? Is it true, as an illustrious modern critic¹⁷ has said, that 'the greatest didactic poem in any language was written in defence of the silliest and meanest of all systems of natural and moral philosophy'? Is this work a mere maze of ingeniously woven error, enriched with a few brilliant colours which have not yet faded with the lapse of time? or is it a great monument of the ancient mind, marking indeed its limitations, but at the same time perpetuating the memory of its native strength and energy? Has all the meaning of this controversy between science in its infancy and the pagan mythology in its decrepitude passed away, as from the vantage-ground of nineteen centuries the blindness and the ignorance of both combatants are apparent? Or, may we not rather discern that amid all the confusion of this dim νυκτομαχία a great cause was at issue; that truths the most vital to human wellbeing were involved on both sides; and that some positions were then gained which are not now abandoned?

In estimating the strength and the weakness of the system expounded by Lucretius, it is necessary to distinguish between the exposition of the principles of the atomic philosophy, contained in the first two books, and the explanation of natural phenomena contained in the remaining books. The first, notwithstanding some arbitrary and unverifiable assumptions, represents a real and important stage in the progress of enquiry; the second, although containing many striking observations and immediate inferences from the facts and processes of Nature, is, from the point of view of modern science, to be regarded mainly, as a curious page in the records of human error. Whatever may be said of the Epicurean additions to the system, it seems to be admitted that the original hypothesis of Democritus has been more pregnant in results, and has more affinity with the most advanced physical speculations of modern times, than the doctrines of all the other philosophers of antiquity. But even amid the mass of unwarranted assumptions and erroneous explanations contained in the later books, the topics discussed—such as the relation of the mind to the body, the mode by which sensible impressions are conveyed to the mind, the processes by which our globe assumed its present form, the origin of life, the evolution of humanity from its lowest to its higher stages of development, the origin of spiritual beliefs, of the humaner sentiments, of language, etc.—possess the interest of being kindred to those on which speculative activity is most employed in the present day. If the study of Lucretius forces upon our minds the arbitrary assumptions, the inadequate method, and the false conclusions of ancient science, it enables us to appreciate the disinterested greatness of its aims, and the enlightened curiosity which sought to solve the vastest problems.

It might be said, generally, that the argument of Lucretius was an attempt to give a philosophical description of Nature before the advent of physical science. But, as a means of throwing light on the inadequacy of such speculations, it may be well to consider in detail some of those points where the argument most obviously fails in premises, method, and results.

The ancient as well as the modern enquirer into the truth of things was confronted with the question of the origin of all our knowledge. Is knowledge obtained originally through the exercise of the reason or the senses, or through their combined and inseparable action? To this question Lucretius distinctly answers, that the senses are the foundation of all our knowledge.¹⁸ They are our 'prima fides': the basis not only of all sound inference, but of all human conduct. The very conception of the meaning of true and false is derived from the senses:—