The attempts to explain the nature of Life, which have fallen within my knowledge, presuppose the arbitrary division of all that surrounds us into things with life, and things without life—a division grounded on a mere assumption. At the best, it can be regarded only as a hasty deduction from the first superficial notices of the objects that surround us, sufficient, perhaps, for the purpose of ordinary discrimination, but far too indeterminate and diffluent to be taken unexamined by the philosophic inquirer. The positions of science must be tried in the jeweller's scales, not like the mixed commodities of the market, on the weigh-bridge of common opinion and vulgar usage. Such, however, has been the procedure in the present instance, and the result has been answerable to the coarseness of the process. By a comprisal of the petitio principii with the argumentum in circulo,—in plain English, by an easy logic, which begins with begging the question, and then moving in a circle, comes round to the point where it began,—each of the two divisions has been made to define the other by a mere reassertion of their assumed contrariety. The physiologist has luminously explained Y plus X by informing us that it is a somewhat that is the antithesis of Y minus X; and if we ask, what [pg 022] then is Y-X? the answer is, the antithesis of Y+X,—a reciprocation of great service, that may remind us of the twin sisters in the fable of the Lamiæ, with but one eye between them both, which each borrowed from the other as either happened to want it; but with this additional disadvantage, that in the present case it is after all but an eye of glass. The definitions themselves will best illustrate our meaning. I will begin with that given by Bichat. “Life is the sum of all the functions by which death is resisted,” in which I have in vain endeavoured to discover any other meaning than that life consists in being able to live. This author, with a whimsical gravity, prefaces his definition with the remark, that the nature of life has hitherto been sought for in abstract considerations; as if it were possible that four more inveterate abstractions could be brought together in one sentence than are here assembled in the words, life, death, function, and resistance. Similar instances might be cited from Richerand and others. The word Life is translated into other more learned words; and this paraphrase of the term is substituted for the definition of the thing, and therefore (as is always the case in every real definition as contra-distinguished from a verbal definition,) for at least a partial solution of the fact. Such as these form the first class.—The second class takes some one particular function of Life common to all living objects,—nutrition, for instance; or, to adopt the phrase most in vogue at present, assimilation, for the purposes of reproduction and growth. Now this, it is evident, can be an appropriate definition only of the very lowest species, as of a Fungus or a Mollusca; and just as comprehensive an idea [pg 023] of the mystery of Life, as a Mollusca might give, can this definition afford. But this is not the only objection. For, first, it is not pretended that we begin with seeking for an organ evidently appropriated to nutrition, and then infer that the substance in which such an organ is found lives. On the contrary, in a number of cases among the obscurer animals and vegetables we infer the organ from the pre-established fact of its life. Secondly, it identifies the process itself with a certain range of its forms, those, namely, by which it is manifested in animals and vegetables. For this, too, no less than the former, presupposes the arbitrary division of all things into not living and lifeless, on which, as I before observed, all these definitions are grounded. But it is sorry logic to take the proof of an affirmative in one thing as the proof of the negative in another. All animals that have lungs breathe, but it would be a childish oversight to deduce the converse, viz. all animals that breathe have lungs. The theory in which the French chemists organized the discoveries of Black, Cavendish, Priestly, Scheele, and other English and German philosophers, is still, indeed, the reigning theory, but rather, it should seem, from the absence of a rival sufficiently popular to fill the throne in its stead, than from the continuance of an implicit belief in its own stability. We no longer at least cherish that intensity of faith which, before Davy commenced his brilliant career, had not only identified it with chemistry itself, but had substituted its nomenclature, even in common conversation, for the far more philosophic language which the human race had abstracted from the laboratory of Nature. I may venture to prophecy that no future [pg 024] Beddoes will make it the corival of the mathematical sciences in demonstrative evidence. I think it a matter of doubt whether, during the period of its supposed infallibility, physiology derived more benefit from the extension, or injury from the misdirection, of its views. Enough of the latter is fresh in recollection to make it but an equivocal compliment to a physiological position, that it must stand or fall with the corpuscular philosophy, as modified by the French theory of chemistry. Yet should it happen (and the event is not impossible, nor the supposition altogether absurd,) that more and more decisive facts should present themselves in confirmation of the metamorphosis of elements, the position that life consists in assimilation would either cease to be distinctive, or fall back into the former class as an identical proposition, namely, that Life, meaning by the word that sort of growth which takes place by means of a peculiar organization, consists in that sort of growth which is peculiar to organized life. Thirdly, the definition involves a still more egregious flaw in the reasoning, namely, that of cum hoc, ergo propter hoc (or the assumption of causation from mere coexistence); and this, too, in its very worst form. For it is not cum hoc solo, ergo propter hoc, which would in many cases supply a presumptive proof by induction, but cum hoc, et plurimis aliis, ergo propter hoc! Shell, of some kind or other, is common to the whole order of testacea, but it would be absurd to define the vis vitæ of testaceous animals as existing in the shell, though we know it to be the constant accompaniment, and have every reason to believe the constant effect, of the specific life that acts in those animals. Were we (argumenti [pg 025] causá) to imagine shell coextensive with the organized creation, this would produce no abatement in the falsity of the reasoning. Nor does the flaw stop here; for a physiological, that is a real, definition, as distinguished from the verbal definitions of lexicography, must consist neither in any single property or function of the thing to be defined, nor yet in all collectively, which latter, indeed, would be a history, not a definition. It must consist, therefore, in the law of the thing, or in such an idea of it, as, being admitted, all the properties and functions are admitted by implication. It must likewise be so far causal, that a full insight having been obtained of the law, we derive from it a progressive insight into the necessity and generation of the phenomena of which it is the law. Suppose a disease in question, which appeared always accompanied with certain symptoms in certain stages, and with some one or more symptoms in all stages—say deranged digestion, capricious alternation of vivacity and languor, headache, dilated pupil, diminished sensibility to light, &c.—Neither the man who selected the one constant symptom, nor he who enumerated all the symptoms, would give the scientific definition talem scilicet, quali scientia fit vel datur, but the man who at once named and defined the disease hydrocephalus, producing pressure on the brain. For it is the essence of a scientific definition to be causative, not by introduction of imaginary somewhats, natural or supernatural under the name of causes, but by announcing the law of action in the particular case, in subordination to the common law of which all the phenomena are modifications or results.

The third class, and far superior to the two former, selects some property characteristic of all living bodies, not merely found in all animals alike, but existing equally in all parts of all living things, both animals and plants. Such, for instance, is the definition of Life, as consisting in anti-putrescence, or the power of resisting putrefaction. Like all the others, however, even this confines the idea of Life to those degrees or concentrations of it, which manifest themselves in organized beings, or rather in those the organization of which is apparent to us. Consequently, it substitutes an abstract term, or generalization of effects, for the idea, or superior form of causative agency. At best, it describes the vis vitá by one only of its many influences. It is however, as we have said before, preferable to the former, because it is not, as they are, altogether unfruitful, inasmuch as it attests, less equivocally than any other sign, the presence or absence of that degree of the vis vitá which is the necessary condition of organic or self-renewing power. It throws no light, however, on the law or principle of action; it does not increase our insight into the other phenomena; it presents to us no inclusive form, out of which the other forms may be developed, and finally, its defect as a definition may be detected by generalizing it into a higher formula, as a power which, during its continuance, resists or subordinates heterogeneous and adverse powers. Now this holds equally true of chemical relatively to the mechanical powers; and really affirms no more of Life than may be equally affirmed of every form of being, namely, that it tends to preserve itself, and resists, to a certain extent, whatever is incompatible with the laws that constitute its particular state for the [pg 028] time being. For it is not true only of the great divisions or classes into which we have found it expedient to distinguish, while we generalize, the powers acting in nature, as into intellectual, vital, chemical, mechanical; but it holds equally true of the degrees, or species of each of these genera relatively to each other: as in the decomposition of the alkalies by heat, or the galvanic spark. Like the combining power of Life, the copula here resists for awhile the attempts to dissolve it, and then yields, to reappear in new phenomena.

It is a wonderful property of the human mind, that when once a momentum has been given to it in a fresh direction, it pursues the new path with obstinate perseverance, in all conceivable bearings, to its utmost extremes. And by the startling consequences which arise out of these extremes, it is first awakened to its error, and either recalled to some former track, or receives some fresh impulse, which it follows with the same eagerness, and admits to the same monopoly. Thus in the 13th century the first science which roused the intellects of men from the torpor of barbarism, was, as in all countries ever has been, and ever must be the case, the science of Metaphysics and Ontology. We first seek what can be found at home, and what wonder if truths, that appeared to reveal the secret depths of our own souls, should take possession of the whole mind, and all truths appear trivial which could not either be evolved out of similar principles, by the same process, or at least brought under the same forms of thought, by perceived or imagined analogies? And so it was. For more than a century men continued to invoke the oracle of their own spirits, not only concerning its own forms [pg 029] and modes of being, but likewise concerning the laws of external nature. All attempts at philosophical explication were commenced by a mere effort of the understanding, as the power of abstraction; or by the imagination, transferring its own experiences to every object presented from without. By the former, a class of phenomena were in the first place abstracted, and fixed in some general term: of course this could designate only the impressions made by the outward objects, and so far, therefore, having been thus metamorphosed, they were effects of these objects; but then made to supply the place of their own causes, under the name of occult qualities. Thus the properties peculiar to gold, were abstracted from those it possessed in common with other bodies, and then generalized in the term Aureity: and the inquirer was instructed that the Essence of Gold, or the cause which constituted the peculiar modification of matter called gold, was the power of aureity. By the latter, i.e. by the imagination, thought and will were superadded to the occult quality, and every form of nature had its appropriate Spirit, to be controlled or conciliated by an appropriate ceremonial. This was entitled its SUBSTANTIAL FORM. Thus, physic became a sort of dull poetry, and the art of medicine (for physiology could scarcely be said to exist) was a system of magic, blended with traditional empiricism. Thus the forms of thought proceeded to act in their own emptiness, with no attempt to fill or substantiate them by the information of the senses, and all the branches of science formed so many sections of logic and metaphysics. And so it continued, even to the time that the Reformation sounded the second trumpet, and the authority of the schools sank [pg 030] with that of the hierarchy, under the intellectual courage and activity which this great revolution had inspired. Power, once awakened, cannot rest in one object. All the sciences partook of the new influences. The world of experimental philosophy was soon mapped out for posterity by the comprehensive and enterprising genius of Bacon, and the laws explained by which experiment could be dignified into experience.2 But no sooner was the impulse given, than the same propensity was made manifest of looking at all things in the one point of view which chanced to be of predominant attraction. Our Gilbert, a man of genuine philosophical genius, had no sooner multiplied the facts of magnetism, and extended our knowledge concerning the property of magnetic bodies, but all things in heaven, and earth, and in the waters beneath the earth, were resolved into magnetic influences.

Shortly after a new light was struck by Harriott and Descartes, with their contemporaries, or immediate predecessors, and the restoration of ancient geometry, aided by the modern invention of algebra, placed the science of mechanism on the philosophic throne. How widely this domination spread, and how long it continued, if, indeed, even now it can be said to have abdicated its pretensions, the reader need not be reminded. The sublime discoveries of Newton, and, together with these, his not less fruitful than wonderful application, of the higher mathesis to the movements of the celestial bodies, and to the laws of light, gave almost a religious sanction to the [pg 031] corpuscular system and mechanical theory. It became synonymous with philosophy itself. It was the sole portal at which truth was permitted to enter. The human body was treated of as an hydraulic machine, the operations of medicine were solved, and alas! even directed by reference partly to gravitation and the laws of motion, and partly by chemistry, which itself, however, as far as its theory was concerned, was but a branch of mechanics working exclusively by imaginary wedges, angles, and spheres. Should the reader chance to put his hand on the “Principles of Philosophy,” by La Forge, an immediate disciple of Descartes, he may see the phenomena of sleep solved in a copper-plate engraving, with all the figures into which the globules of the blood shaped themselves, and the results demonstrated by mathematical calculations. In short, from the time of Kepler3 to that of Newton, and from Newton to Hartley, not only all things in external nature, but the subtlest mysteries of life and organization, and even of the intellect and moral being, were conjured within the magic circle of mathematical formulæ. And now a new light was struck by the discovery of electricity, and, in every sense of the word, both playful and serious, both for good and for evil, it may be affirmed to have electrified the whole frame of natural philosophy. Close on its heels followed the momentous discovery of the principal gases by Scheele and Priestly, the composition of water by Cavendish, and the doctrine of latent heat by Black. The scientific world was prepared for a new dynasty; accordingly, as soon as Lavoisier had reduced [pg 032] the infinite variety of chemical phenomena to the actions, reactions, and interchanges of a few elementary substances, or at least excited the expectation that this would speedily be effected, the hope shot up, almost instantly, into full faith, that it had been effected. Henceforward the new path, thus brilliantly opened, became the common road to all departments of knowledge: and, to this moment, it has been pursued with an eagerness and almost epidemic enthusiasm which, scarcely less than its political revolutions, characterise the spirit of the age. Many and inauspicious have been the invasions and inroads of this new conqueror into the rightful territories of other sciences; and strange alterations have been made in less harmless points than those of terminology, in homage to an art unsettled, in the very ferment of imperfect discoveries, and either without a theory, or with a theory maintained only by composition and compromise. Yet this very circumstance has favoured its encroachments, by the gratifications which its novelty affords to our curiosity, and by the keener interest and higher excitement which an unsettled and revolutionary state is sure to inspire. He who supposes that science possesses an immunity from such influences knows little of human nature. How, otherwise, could men of strong minds and sound judgments have attempted to penetrate by the clue of chemical experiment the secret recesses, the sacred adyta of organic life, without being aware that chemistry must needs be at its extreme limits, when it has approached the threshold of a higher power? Its own transgressions, however, and the failure of its enterprises will become the means of defining its absolute boundary, and we shall have to guard [pg 033] against the opposite error of rejecting its aid altogether as analogy, because we have repelled its ambitious claims to an identity with the vital powers.

Secondly. Convinced—by revelation, by the consenting authority of all countries, and of all ages, by the imperative voice of my own conscience, and by that wide chasm between man and the noblest animals of the brute creation, which no perceivable or conceivable difference of organization is sufficient to overbridge—that I have a rational and responsible soul, I think far too reverentially of the same to degrade it into an hypothesis, and cannot be blind to the contradiction I must incur, if I assign that soul which I believe to constitute the peculiar nature of man as the cause of functions and properties, which man possesses in common with the oyster and the mushroom.4

Thirdly, while I disclaim the error of Stahl in deriving the phenomena of life from the unconscious actions of the rational soul, I repel with still greater earnestness the assertion and even the supposition that the functions are the offspring of the structure, and “Life5 the result of organization,” connected with it as effect with cause. Nay, the position seems to me little less strange, than as if a man should say, that building with all the included handicraft, of plastering, sawing, planing, &c. were the offspring of the house; and that the mason and carpenter were the result of a suite of chambers, with the passages and staircases that lead to them. To make A the offspring of B, when the very existence of B as B presupposes the existence of A, is preposterous in the literal sense of the word, and a consummate instance of the hysteron proteron in logic. But if I reject the organ as the cause of that, of which it is the organ, though I might admit it among the conditions of its actual functions; for the same reason, I must reject fluids and ethers of all kinds, magnetical, electrical, and universal, to whatever quintessential thinness they may be treble distilled, and (as it were) super-substantiated. With these, I abjure likewise all chemical agencies, compositions, and decompositions, were it only that as stimulants they suppose a stimulability sui generis, which is but another paraphrase [pg 035] for life. Or if they are themselves at once both the excitant and the excitability, I miss the connecting link between this imaginary ether and the visible body, which then becomes no otherwise distinguished from inanimate matter, than by its juxtaposition in mere space, with an heterogeneous inmate, the cycle of whose actions revolves within itself. Besides which I should think that I was confounding metaphors and realities most absurdly, if I imagined that I had a greater insight into the meaning and possibility of a living alcohol, than of a living quicksilver. In short, visible surface and power of any kind, much more the power of life, are ideas which the very forms of the human understanding make it impossible to identify. But whether the powers which manifest themselves to us under certain conditions in the forms of electricity, or chemical attraction, have any analogy to the power which manifests itself in growth and organization, is altogether a different question, and demands altogether a different chain of reasoning: if it be indeed a tree of knowledge, it will be known by its fruits, and these will depends not on the mere assertion, but on the inductions by which the position is supported, and by the additions which it makes to our insight into the nature of the facts it is meant to illustrate.

To account for Life is one thing; to explain Life another. In the first we are supposed to state something prior (if not in time, yet in the order of Nature) to the thing accounted for, as the ground or cause of that thing, or (which comprises the meaning and force of both words) as its sufficient cause, quae et facit, et subest. And to this, in the question of Life, I know no possible answer, but GOD. To account for a thing is to see into the [pg 036] principle of its possibility, and from that principle to evolve its being. Thus the mathematician demonstrates the truths of geometry by constructing them. It is an admirable remark of Joh. Bapt. a Vico, in a Tract published at Naples, 1710,6 “Geometrica ideò demonstramus, quia facimus; physica si demonstrare possimus, faceremus. Metaphysici veri claritas eadem ac lucis, quam non nisi per opaca cognoscimus; nam non lucem sed lucidas res videmus. Physica sunt opaca, nempe formata et finita, in quibus Metaphysici veri lumen videmus.” The reasoner who assigns structure or organization as the antecedent of Life, who names the former a cause, and the latter its effect, he it is who pretends to account for life. Now Euclid would, with great right, demand of such a philosopher to make Life; in the same sense, I mean, in which Euclid makes an Icosahedron, or a figure of twenty sides, namely, in the understanding or by an intellectual construction. An argument which, of itself, is sufficient to prove the untenable nature of Materialism.

To explain a power, on the other hand, is (the power itself being assumed, though not comprehended, ut qui datur, non intelligitur) to unfold or spread it out: ex implicito planum facere. In the present instance, such an explanation would consist in the reduction of the idea of Life to its simplest and most comprehensive form or mode of action; that is, to some characteristic instinct or tendency, evident in all its manifestations, and involved in the idea itself. This assumed as existing in kind, it will be required to present an ascending series of corresponding [pg 037] phenomena as involved in, proceeding from, and so far therefore explained by, the supposition of its progressive intensity and of the gradual enlargement of its sphere, the necessity of which again must be contained in the idea of the tendency itself. In other words, the tendency having been given in kind, it is required to render the phenomena intelligible as its different degrees and modifications. Still more perfect will the explanation be, should the necessity of this progression and of these ascending gradations be contained in the assumed idea of life, as thus defined by the general form and common purport of all its various tendencies. This done, we have only to add the conditions common to all its phenomena, and, those appropriate to each place and rank, in the scale of ascent, and then proceed to determine the primary and constitutive forms, i.e. the elementary powers in which this tendency realizes itself under different degrees and conditions.7

What is Life? Were such a question proposed, we should be tempted to answer, what is not Life that really is? Our reason convinces us that the quantities of things, taken abstractedly as quantity, exist only in the relations they bear to the percipient; in plainer words, they exist [pg 039] only in our minds, ut quorum esse est percipi. For if the definite quantities have a ground, and therefore a reality, in the external world, and independent of the mind that perceives them, this ground is ipso facto a quality; the very etymon of this world showing that a quality, not taken in its own nature but in relation to another thing, is to be defined causa sufficiens, entia, de quibus loquimur; esse talia, qualia sunt. Either the quantities perceived exist only in the perception, or they have likewise a real existence. In the former case, the quality (the word is here used in an active sense) that determines them belongs to Life, per ipsam hypothesin; and in the other case, since by the agreement of all parties Life may exist in other forms than those of consciousness, or even of sensibility, the onus probandi falls on those who assert of any quality that it is not Life. For the analogy of all that we know is clearly in favour of the contrary supposition, and if a man would analyse the meaning of his own words, and carefully distinguish his perceptions and sensations from the external cause exciting them, and at the same time from the quantity or superficies under which that cause is acting, he would instantly find himself, if we mistake not, involuntarily identifying the ideas of Quality and Life. Life, it is admitted on all hands, does not necessarily imply consciousness or sensibility; and we, for our parts, cannot see that the irritability which metals manifest to galvanism, can be more remote from that which may be supposed to exist in the tribe of lichens, or in the helvellæ, pezizee, &c., than the latter is from the phenomena of excitability in the human body, whatever name it may be called by, or in [pg 040] whatever way it may modify itself.8 That the mere act of growth does not constitute the idea of Life, or the absence of that act exclude it, we have a proof in every egg before it is placed under the hen, and in every grain of corn before it is put into the soil. All that could be deduced by fair reasoning would amount to this only, that the life of metals, as the power which effects and determines their comparative cohesion, ductility, &c., was yet lower on the scale than the Life which produces the first attempts of organization, in the almost shapeless tremella, or in such fungi as grow in the dark recesses of the mine.

If it were asked, to what purpose or with what view we should generalize the idea of Life thus broadly, I should not hesitate to reply that, were there no other use conceivable, there would be some advantage in merely destroying an arbitrary assumption in natural philosophy, and in reminding the physiologists that they could not hear the life of metals asserted with a more contemptuous surprise than they themselves incur from the vulgar, when they speak of the Life in mould or mucor. But this is not the case. This wider view not only precludes a groundless assumption, it likewise fills up the arbitrary chasm between physics and physiology, and justifies us in using the former as means of insight into the latter, which would be contrary to all sound rules of ratiocination if the powers working in the objects of the two sciences were absolutely [pg 041] and essentially diverse. For as to abstract the idea of kind from that of degrees, which are alone designated in the language of common use, is the first and indispensable step in philosophy, so are we the better enabled to form a notion of the kind, the lower the degree, and the simpler the form is in which it appears to us. We study the complex in the simple; and only from the intuition of the lower can we safely proceed to the intellection of the higher degrees. The only danger lies in the leaping from low to high, with the neglect of the intervening gradations. But the same error would introduce discord into the gamut, et ab abusu contra usum non valet consequentia. That these degrees will themselves bring forth secondary kinds sufficiently distinct for all the purposes of science, and even for common sense, will be seen in the course of this inquisition: for this is one proof of the essential vitality of nature, that she does not ascend as links in a suspended chain, but as the steps in a ladder; or rather she at one and the same time ascends as by a climax, and expands as the concentric circles on the lake from the point to which the stone in its fall had given the first impulse. At all events, a contemptuous rejection of this mode of reasoning would come with an ill grace from a medical philosopher, who cannot combine any three phenomena of health or of disease without the assumption of powers, which he is compelled to deduce without being able to demonstrate; nay, even of material substances as the vehicles of these powers, which he can never expect to exhibit before the senses.

From the preceding it should appear, that the most comprehensive formula to which life is reducible, would [pg 042] be that of the internal copula of bodies, or (if we may venture to borrow a phrase from the Platonic school) the power which discloses itself from within as a principle of unity in the many. But that there is a physiognomy in words, which, without reference to their fitness or necessity, make unfavorable as well as favorable impressions, and that every unusual term in an abstruse research incurs the risk of being denominated jargon, I should at the same time have borrowed a scholastic term, and defined life absolutely, as the principle of unity in multeity, as far as the former, the unity to wit, is produced ab intra; but eminently (sensu eminenti), I define life as the principle of individuation, or the power which unites a given all into a whole that is presupposed by all its parts. The link that combines the two, and acts throughout both, will, of course, be defined by the tendency to individuation. Thus, from its utmost latency, in which life is one with the elementary powers of mechanism, that is, with the powers of mechanism considered as qualitative and actually synthetic, to its highest manifestation, (in which, as the vis vitæ vivida, or life as life, it subordinates and modifies these powers, becoming contra-distinguished from mechanism,9 ab extra, under the form of organization,) there is an ascending series of intermediate classes, and of analogous gradations in each class. To a reflecting mind, indeed, the very fact that the powers peculiar to life in living animals include cohesion, elasticity, &c. (or, in the words of a late publication, “that living matter exhibits [pg 043] these physical properties,”10) would demonstrate that, in the truth of things, they are homogeneous, and that both the classes are but degrees and different dignities of one and the same tendency. For the latter are not subjected to the former as a lever, or walking-stick to the muscles; the more intense the life is, the less does elasticity, for instance, appear as elasticity. It sinks down into the nearest approach to its physical form by a series of degrees from the contraction and elongation of the irritable muscle to the physical hardness of the insensitive nail. The lower powers are assimilated, not merely employed, and assimilation presupposes the homogeneous nature of the thing assimilated; else it is a miracle, only not the same as that of a creation, because it would imply that additional and equal miracle of annihilation. In short, all the impossibilities which the acutest of the reformed Divines have detected in the hypothesis of transubstantiation would apply, totidem verbis et syllabis, to that of assimilation, if the objects and the agents were really heterogeneous. Unless, therefore, a thing can exhibit properties which do not belong to it, the very admission that living matter exhibits physical properties, includes the further admission, that those physical or dead properties are themselves vital in essence, really distinct but [pg 044] in appearance only different; or in absolute contrast with each other.

Finally, of individuals, the living power will be most intense in that individual which, as a whole, has the greatest number of integral parts presupposed in it; when, moreover, these integral parts, together with a proportional increase of their interdependence, as parts, have themselves most [pg 045] the character of wholes in the sphere occupied by them. A mathematical point, line, or surface, is an ens rationis, for it expresses an intellectual act; but a physical atom is ens fictitium, which may be made subservient, as ciphers are in arithmetic, to the purposes of hypothetical construction, per regulam falsi; but transferred to Nature, it is in the strictest sense an absurd quantity; for extension, and consequently divisibility, or multeity,11 (for space cannot be divided,) is the indispensable condition, under which alone anything can appear to us, or even be thought of, as a thing. But if it should be replied, that the elementary particles are atoms not positively, but by such a hardness communicated to them as is relatively invincible, I should remind the assertor that temeraria citatio supernaturalium est pulvinar intellectús pigri, and that he who requires me to believe a miracle of his own dreaming, must first work a miracle to convince me that he had dreamt by inspiration. Add, too, the gross inconsistency of resorting to an immaterial influence in order to complete a system of materialism, by the exclusion of all modes of existence which the theorist cannot in imagination, at least, finger and peep at! Each of the preceding gradations, as above defined, might be represented as they exist, and are realised in Nature. But each would require a work for itself, [pg 046] co-extensive with the science of metals, and that of fossils (both as geologically applied); of crystallization; and of vegetable and animal physiology, in all its distinct branches. The nature of the present essay scarcely permits the space sufficient to illustrate our meaning. The proof of its probability (for to that only can we arrive by so partial an application of the hypothesis), is to be found in its powers of solving the particular class of phenomena, that form the subjects of the present inquisition, more satisfactorily and profitably than has been done, or even attempted before.

Exclusively, therefore, for the purposes of illustration, I would take as an instance of the first step, the metals, those, namely, that are capable of permanent reduction. For, by the established laws of nomenclature, the others (as sodium, potassium, calcium, silicium, &c.) would be entitled to a class of their own, under the name of bases. It is long since the chemists have despaired of decomposing this class of bodies. They still remain, one and all, as elements or simple bodies, though, on the principles of the corpuscularian philosophy, nothing can be more improbable than that they really are such; and no reason has or can be assigned on the grounds of that system, why, in no one instance, the contrary has not been proved. But this is at once explained, if we assume them as the simplest form of unity, namely, the unity of powers and properties. For these, it is evident, may be endlessly modified, but can never be decomposed. If I were asked by a philosopher who had previously extended the attribute of Life to the Byssus speciosa, and even to the crustaceous matter, or outward bones of a lobster, &c., whether [pg 047] the ingot of gold expressed life, I should answer without hesitation, as the ingot of gold assuredly not, for its form is accidental and ab extra. It may be added to or detracted from without in the least affecting the nature, state, or properties in the specific matter of which the ingot consists. But as gold, as that special union of absolute and of relative gravity, ductility, and hardness, which, wherever they are found, constitute gold, I should answer no less fearlessly, in the affirmative. But I should further add, that of the two counteracting tendencies of nature, namely, that of detachment from the universal life, which universality is represented to us by gravitation, and that of attachment or reduction into it, this and the other noble metals represented the units in which the latter tendency, namely, that of identity with the life of nature, subsisted in the greatest overbalance over the former. It is the form of unity with the least degree of tendency to individuation.

In the first step, we had Life, as the mere unity of powers; in the second we have the simplest forms of totality evolved. The third step is presented to us in those vast formations, the tracing of which generically would form the science of Geology, or its history in the [pg 048] strict sense of the word, even as their description and diagnostics constitute its preliminaries.

In the treatment of a subject so vast and complex, within the limits prescribed for an essay like the present, where it is impossible not to say either too much or too little (and too much because too little), an author is entitled to make large claims on the candour of his judges. Many [pg 049] things he must express inaccurately, not from ignorance or oversight, but because the more precise expression would have involved the necessity of a further explanation, and this another, even to the first elements of the science. This is an inconvenience which presses on the analytic method, on however large a scale it may be conducted, compared with the synthetic; and it must bear with a tenfold weight in the present instance, where we are not permitted to avail ourselves of its usual advantages as a counterbalance to its inherent defects. I shall have done all that I dared propose to myself, or that can be justly demanded of me by others, if I have succeeded in conveying a sufficiently clear, though indistinct and inadequate notion, so as of its many results to render intelligible that one which I am to apply to my particular subject, not as a truth already demonstrated, but as an hypothesis, which pretends to no higher merit than that of explaining the particular class of phenomena to which it is applied, and asks no other reward than a presumption in favour of the general system of which it affirms itself to be a dependent though integral part. By Life I everywhere mean the true Idea of Life, or that most general form under which Life manifests itself to us, which includes all its other forms. This I have stated to be the tendency to individuation, and the degrees or intensities of Life to consist in the progressive realization of this tendency. The power which is acknowledged to exist, wherever the realization is found, must subsist wherever the tendency is manifested. The power which comes forth and stirs abroad in the bird, must be latent in the egg. I have shown, moreover, that this tendency to [pg 050] individuate cannot be conceived without the opposite tendency to connect, even as the centrifugal power supposes the centripetal, or as the two opposite poles constitute each other, and are the constituent acts of one and the same power in the magnet. We might say that the life of the magnet subsists in their union, but that it lives (acts or manifests itself) in their strife. Again, if the tendency be at once to individuate and to connect, to detach, but so as either to retain or to reproduce attachment, the individuation itself must be a tendency to the ultimate production of the highest and most comprehensive individuality. This must be the one great end of Nature, her ultimate object, or by whatever other word we may designate that something which bears to a final cause the same relation that Nature herself bears to the Supreme Intelligence.