Chapter V: Book I

APHORISMS CONCERNING IDEAS DERIVED FROM THE HISTORY OF IDEAS.

I.

_MAN is the Interpreter of Nature, Science the right interpretation._ (_History of Scientific Ideas_: Book I. Chapter 1.)

II.

_The_ Senses _place before us the_ Characters _of the Book of Nature; but these convey no knowledge to us, till we have discovered the Alphabet by which they are to be read._ (Ibid. I. 2.)

III.

_The_ Alphabet, _by means of which we interpret Phenomena, consists of the_ Ideas _existing in our own minds; for these give to the phenomena that coherence and significance which is not an object of sense._ (I. 2.)

IV.

_The antithesis of_ Sense _and_ Ideas _is the foundation of the Philosophy of Science. No knowledge can exist without the union, no philosophy without the separation, of these two elements._ (I. 2.) {6}

V.

Fact _and_ Theory _correspond to Sense on the one hand, and to Ideas on the other, so far as we are_ conscious _of our Ideas: but all facts involve ideas_ unconsciously; _and thus the distinction of Facts and Theories is not tenable, as that of Sense and Ideas is._ (I. 2.)

VI.

_Sensations and Ideas in our knowledge are like Matter and Form in bodies. Matter cannot exist without Form, nor Form without Matter: yet the two are altogether distinct and opposite. There is no possibility either of separating, or of confounding them. The same is the case with Sensations and Ideas._ (I. 2.)

VII.

_Ideas are not_ trans_formed, but_ in_formed Sensations; for without ideas, sensations have no form._ (I. 2.)

VIII.

_The Sensations are the_ Objective, _the Ideas the_ Subjective _part of every act of perception or knowledge._ (I. 2.)

IX.

_General Terms denote_ Ideal Conceptions, _as a_ circle, _an_ orbit, _a_ rose. _These are not_ Images _of real things, as was held by the Realists, but Conceptions: yet they are conceptions, not bound together by mere_ Name, _as the Nominalists held, but by an Idea._ (I. 2.)

X.

_It has been said by some, that all Conceptions are merely_ states _or_ feelings of the mind, _but this assertion only tends to confound what it is our business to distinguish._ (I. 2.)

XI.

_Observed Facts are connected so as to produce new truths, by superinducing upon them an Idea: and such truths are obtained_ by Induction. (I. 2.) {7}

XII.

_Truths once obtained by legitimate Induction are Facts: these Facts may be again connected, so as to produce higher truths: and thus we advance to_ Successive Generalizations. (I. 2.)

XIII.

_Truths obtained by Induction are made compact and permanent by being expressed in_ Technical Terms. (I. 3.)

XIV.

_Experience cannot conduct us to universal and necessary truths:--Not to universal, because she has not tried all cases:--Not to necessary, because necessity is not a matter to which experience can testify._ (I. 5.)

XV.

_Necessary truths derive their necessity from the_ Ideas _which they involve; and the existence of necessary truths proves the existence of Ideas not generated by experience._ (I. 5.)

XVI.

_In Deductive Reasoning, we cannot have any truth in the conclusion which is not virtually contained in the premises._ (I. 6.)

XVII.

_In order to acquire any exact and solid knowledge, the student must possess with perfect precision the ideas appropriate to that part of knowledge: and this precision is tested by the student's_ perceiving _the axiomatic evidence of the_ axioms _belonging to each_ Fundamental Idea. (I. 6.)

XVIII.

_The Fundamental Ideas which it is most important to consider, as being the Bases of the Material Sciences, are the Ideas of_ Space, Time (_including Number_), Cause (_including Force and Matter_), Outness _of Objects, and_ Media _of Perception of Secondary Qualities,_ Polarity (_Contrariety_), {8} _Chemical_ Composition _and_ Affinity, Substance, Likeness _and Natural_ Affinity, Means and Ends (_whence the Notion of Organization_), Symmetry, _and the Ideas of_ Vital Powers. (I. 8.)

XIX.

_The Sciences which depend upon the Ideas of Space and Number are_ Pure _Sciences, not_ Inductive _Sciences: they do not infer special Theories from Facts, but deduce the conditions of all theory from Ideas. The Elementary Pure Sciences, or Elementary Mathematics, are Geometry, Theoretical Arithmetic and Algebra._ (II. 1.)

XX.

_The Ideas on which the Pure Sciences depend, are those of_ Space _and_ Number; _but Number is a modification of the conception of Repetition, which belongs to the Idea of_ Time. (II. 1.)

XXI.

_The_ Idea of Space _is not derived from experience, for experience of external objects_ pre_supposes bodies to exist in Space, Space is a condition under which the mind receives the impressions of sense, and therefore the relations of space are necessarily and universally true of all perceived objects. Space is a_ form _of our perceptions, and regulates them, whatever the_ matter _of them may be._ (II. 2.)

XXII.

_Space is not a General Notion collected by abstraction from particular cases; for we do not speak of_ Spaces _in general, but of universal or absolute_ Space. _Absolute Space is infinite. All special spaces are_ in _absolute space, and are parts of it._ (II. 3.)

XXIII.

_Space is not a real object or thing, distinct from the objects which exist in it; but it is a real condition of the existence of external objects._ (II. 3.) {9}

XXIV.

_We have an_ Intuition _of objects in space; that is, we contemplate objects as_ made up _of spatial parts, and apprehend their spatial relations by the same act by which we apprehend the objects themselves._ (II. 3.)

XXV.

Form _or Figure is space limited by boundaries. Space has necessarily_ three _dimensions, length, breadth, depth; and no others which cannot be resolved into these._ (II. 3.)

XXVI.

_The Idea of Space is exhibited for scientific purposes, by the_ Definitions _and_ Axioms _of Geometry; such, for instance, as these:--the_ Definition of a Right Angle, _and_ of a Circle;--_the_ Definition of Parallel Lines, _and the_ Axiom _concerning them;--the_ Axiom _that_ two straight lines cannot inclose a space. _These Definitions are necessary, not arbitrary; and the Axioms are needed as well as the Definitions, in order to express the necessary conditions which the Idea of Space imposes._ (II. 4.)

XXVII.

_The Definitions and Axioms of Elementary Geometry do not_ completely _exhibit the Idea of Space. In proceeding to the Higher Geometry, we may introduce other additional and independent Axioms; such as that of Archimedes, that_ a curve line which joins two points is less than any broken line joining the same points and including the curve line. (II. 4.)

XXVIII.

_The perception of a_ solid object _by sight requires that act of mind by which, from figure and shade, we infer distance and position in space. The perception of_ figure _by sight requires that act of mind by which we give an outline to each object._ (II. 6.) {10}

XXIX.

_The perception of Form by touch is not an impression on the passive sense, but requires an act of our muscular frame by which we become aware of the position of our own limbs. The perceptive faculty involved in this act has been called_ the muscular sense. (II. 6.)

XXX.

_The_ Idea of Time _is not derived from experience, for experience of changes_ pre_supposes occurrences to take place in Time. Time is a condition under which the mind receives the impressions of sense, and therefore the relations of time are necessarily and universally true of all perceived occurrences. Time is a_ form _of our perceptions, and regulates them, whatever the_ matter _of them may be._ (II. 7.)

XXXI.

_Time is not a General Notion collected by abstraction from particular cases. For we do not speak of particular_ Times _as examples of time in general, but as parts of a single and infinite_ Time. (II. 8.)

XXXII.

_Time, like Space, is a form, not only of perception, but of_ Intuition. _We consider the whole of any time as_ equal _to the_ sum _of the parts; and an occurrence as_ coinciding _with the portion of time which it occupies._ (II. 8.)

XXXIII.

_Time is analogous to Space of_ one dimension: _portions of both have a beginning and an end, are long or short. There is nothing in Time which is analogous to Space of two, or of three, dimensions, and thus nothing which corresponds to Figure._ (II. 8.)

XXXIV.

_The Repetition of a set of occurrences, as, for example, strong and weak, or long and short sounds, according to a_ {11} _steadfast order, produces_ Rhythm, _which is a conception peculiar to Time, as Figure is to Space._ (II. 8.)

XXXV.

_The simplest form of Repetition is that in which there is no variety, and thus gives rise to the conception of_ Number. (II. 8.)

XXXVI.

_The simplest numerical truths are seen by Intuition; when we endeavour to deduce the more complex from these simplest, we employ such maxims as these_:--If equals be added to equals the wholes are equal:--If equals be subtracted from equals the remainders are equal:--The whole is equal to the sum of all its parts. (II. 9.)

XXXVII.

_The Perception of Time involves a constant and latent kind of memory, which may be termed a_ Sense of Succession. _The Perception of Number also involves this Sense of Succession, although in small numbers we appear to apprehend the units simultaneously and not successively._ (II. 10.)

XXXVIII.

_The Perception of Rhythm is not an impression on the passive sense, but requires an act of thought by which we connect and group the strokes which form the Rhythm._ (II. 10.)

XXXIX.

Intuitive _is opposed to_ Discursive _reason. In intuition, we obtain our conclusions by dwelling upon_ one _aspect of the fundamental Idea; in discursive reasoning, we combine_ several _aspects of the Idea,_ (_that is, several axioms,_) _and reason from the combination._ (II. 11.)

XL.

_Geometrical deduction_ (_and deduction in general_) _is called_ Synthesis, _because we introduce, at successive steps, the_ {12} _results of new principles. But in reasoning on the relations of space, we sometimes go on_ separating _truths into their component truths, and these into other component truths; and so on: and this is geometrical_ Analysis. (II. 11.)

XLI.

_Among the foundations of the Higher Mathematics, is the_ Idea of Symbols _considered as general_ Signs _of Quantity. This idea of a Sign is distinct from, and independent of other ideas. The Axiom to which we refer in reasoning by means of Symbols of quantity is this_:--The interpretation of such symbols must be perfectly general. _This Idea **and Axiom are the bases of Algebra in its most general form._ (II. 12.)

XLII.

_Among the foundations of the Higher Mathematics is also the_ Idea of a Limit. _The Idea of a Limit cannot be superseded by any other definitions or Hypotheses, The Axiom which we employ in introducing this Idea into our reasoning is this_:--What is true up to the Limit is true at the Limit. _This Idea and Axiom are the bases of all Methods of Limits, Fluxions, Differentials, Variations, and the like._ (II. 12.)

XLIII.

_There is a_ pure _Science of Motion, which does not depend upon observed facts, but upon the Idea of motion. It may also be termed_ Pure Mechanism, _in opposition to Mechanics Proper, or_ Machinery, _which involves the mechanical conceptions of force and matter. It has been proposed to name this Pure Science of Motion,_ Kinematics. (II. 13.)

XLIV.

_The pure Mathematical Sciences must be successfully cultivated, in order that the progress of the principal Inductive Sciences may take place. This appears in the case of Astronomy, in which Science, both in ancient and in modern times, each advance of the theory has depended upon the_ {13} _previous solution of problems in pure mathematics. It appears also inversely in the Science of the Tides, in which, at present, we cannot advance in the theory, because we cannot solve the requisite problems in the Integral Calculus._ (II. 14.)

XLV.

_The_ Idea of Cause, _modified into the conceptions of mechanical cause, or Force, and resistance to force, or Matter, is the foundation of the Mechanical Sciences; that is, Mechanics,_ (_including Statics and Dynamics,_) _Hydrostatics, and Physical Astronomy._ (III. 1.)

XLVI.

_The Idea of Cause is not derived from experience; for in judging of occurrences which we contemplate, we consider them as being, universally and necessarily, Causes and Effects, which a finite experience could not authorize us to do. The Axiom, that every event must have a cause, is true independently of experience, and beyond the limits of experience._ (III. 2.)

XLVII.

_The Idea of Cause is expressed for purposes of science by these three Axioms_:--Every Event must have a Cause:--Causes are measured by their Effects:--Reaction is equal and opposite to Action. (III. 4.)

XLVIII.

_The Conception of Force involves the Idea of Cause, as applied to the motion and rest of bodies. The conception of_ force _is suggested by muscular action exerted: the conception of_ matter _arises from muscular action resisted. We necessarily ascribe to all bodies solidity and inertia, since we conceive Matter as that which cannot be compressed or moved without resistance._ (III. 5.)

XLIX.

_Mechanical Science depends on the Conception of Force; and is divided into_ Statics, _the doctrine of Force preventing_ {14} _motion, and_ Dynamics, _the doctrine of Force producing motion._ (III. 6.)

L.

_The Science of Statics depends upon the Axiom, that Action and Reaction are equal, which in Statics assumes this form_:--When two equal weights are supported on the middle point between them, the pressure on the fulcrum is equal to the sum of the weights. (III. 6.)

LI.

_The Science of Hydrostatics depends upon the Fundamental Principle that_ fluids press equally in all directions. _This principle necessarily results from the conception of a Fluid, as a body of which the parts are perfectly moveable in all directions. For since the Fluid is a body, it can transmit pressure; and the transmitted pressure is equal to the original pressure, in virtue of the Axiom that Reaction is equal to Action. That the Fundamental Principle is not derived from experience, is plain both from its evidence and from its history._ (III. 6.)

LII.

_The Science of Dynamics depends upon the three Axioms above stated respecting Cause. The First Axiom,--that every change must have a Cause,--gives rise to the First Law of Motion,--that_ a body not acted upon by a force will move with a uniform velocity in a straight line. _The Second Axiom,--that Causes are measured by their Effects,--gives rise to the Second Law of Motion,--that_ when a force acts upon a body in motion, the effect of the force is compounded with the previously existing motion. _The Third Axiom,--that_ Reaction is equal and opposite to Action,--_gives rise to the Third Law of Motion, which is expressed in the same terms as the Axiom; Action and Reaction being understood to signify momentum gained and lost._ (III. 7.) {15}

LIII.

_The above Laws of Motion, historically speaking, were established by means of experiment: but since they have been discovered and reduced to their simplest form, they have been considered by many philosophers as self-evident. This result is principally due to the introduction and establishment of terms and definitions, which enable us to express the Laws in a very simple manner._ (III. 7.)

LIV.

_In the establishment of the Laws of Motion, it happened, in several instances, that Principles were assumed as self-evident which do not now appear evident, but which have since been demonstrated from the simplest and most evident principles. Thus it was assumed that_ a perpetual motion is impossible;--_that_ the velocities of bodies acquired by falling down planes or curves of the same vertical height are equal;--_that_ the actual descent of the center of gravity is equal to its potential ascent. _But we are not hence to suppose that these assumptions were made without ground: for since they really follow from the laws of motion, they were probably, in the minds of the discoverers, the results of undeveloped demonstrations which their sagacity led them to divine._ (III. 7.)

LV.

_It is a_ Paradox _that Experience should lead us to truths confessedly universal, and apparently necessary, such as the Laws of Motion are. The_ Solution _of this paradox is, that these laws are interpretations of the Axioms of Causation. The axioms are universally and necessarily true, but the right interpretation of the terms which they involve, is learnt by experience. Our Idea of Cause supplies the_ Form, _Experience, the_ Matter, _of these Laws._ (III. 8.)

LVI.

Primary _Qualities of Bodies are those which we can conceive as directly perceived;_ Secondary _Qualities are those_ {16} _which we conceive as perceived by means of a Medium._ (IV. 1.)

LVII.

_We necessarily perceive bodies as_ without _us; the Idea of_ Externality _is one of the conditions of perception._ (IV. 1.)

LVIII.

_We necessarily assume a_ Medium _for the perceptions of Light, Colour, Sound, Heat, Odours, Tastes; and this Medium_ must _convey impressions by means of its mechanical attributes._ (IV. 1.)

LIX.

_Secondary Qualities are not_ extended _but_ intensive: _their effects are not augmented by addition of parts, but by increased operation of the medium. Hence they are not measured directly, but by_ scales; _not by_ units, _but by_ degrees. (IV. 4.)

LX.

_In the Scales of Secondary Qualities, it is a condition_ (_in order that the scale may be complete,_) _that every example of the quality must either_ agree _with one of the degrees of the Scale, or lie between two_ contiguous _degrees._ (IV. 4.)

LXI.

_We perceive_ by means of _a medium and_ by means of _impressions on the nerves: but we do not_ (_by our senses_) _perceive either the medium or the impressions on the nerves._ (IV. 1.)

LXII.

_The_ Prerogatives of the Sight _are, that by this sense we necessarily and immediately apprehend the_ position _of its objects: and that from visible circumstances, we_ infer _the_ distance _of objects from us, so readily that we seem to perceive and not to infer._ (IV. 2.) {17}

LXIII.

_The_ Prerogatives of the Hearing _are, that by this sense we perceive relations perfectly precise and definite between two notes, namely,_ Musical Intervals (_as an_ Octave, _a_ Fifth); _and that when two notes are perceived together, they are comprehended as distinct,_ (_a_ Chord,) _and as having a certain relation,_ (Concord _or_ Discord.) (IV. 2.)

LXIV.

_The Sight cannot decompose a compound colour into simple colours, or distinguish a compound from a simple colour. The Hearing cannot directly perceive the place, still less the distance, of its objects: we infer these obscurely and vaguely from audible circumstances._ (IV. 2.)

LXV.

_The_ First Paradox of Vision _is, that we see objects_ upright, _though the images on the retina are_ inverted. _The solution is, that we do not see the image on the retina at all, we only see by means of it._ (IV. 2.)

LXVI.

_The_ Second Paradox of Vision _is, that we see objects_ single, _though there are two images on the retinas, one in each eye. The explanation is, that it is a Law of Vision that we see_ (_small or distant_) _objects single, when their images fall on_ corresponding points _of the two retinas._ (IV. 2.)

LXVII.

_The law of single vision for_ near _objects is this:--When the two images in the two eyes are situated, part for part, nearly but not exactly, upon corresponding points, the object is apprehended as single and solid if the two objects are such as would be produced by a single solid object seen by the eyes separately._ (IV. 2.)

LXVIII.

_The ultimate object of each of the Secondary Mechanical Sciences is, to determine the nature and laws of the processes_ {18} _by which the impression of the Secondary Quality treated of is conveyed: but before we discover the cause, it may be necessary to determine the_ laws _of the phenomena; and for this purpose a_ Measure _or_ Scale _of each quality is necessary._ (IV. 4.)

LXIX.

_Secondary qualities are measured by means of such effects as can be estimated in number or space._ (IV. 4.)

LXX.

_The Measure of Sounds, as high or low, is the_ Musical Scale, _or_ Harmonic Canon. (IV. 4.)

LXXI.

_The Measures of Pure Colours are the_ Prismatic Scale; _the same, including_ Fraunhofer's Lines; _and_ Newton's Scale _of Colours. The principal Scales of Impure Colours are_ Werner's Nomenclature _of Colours, and_ Merimée's Nomenclature _of Colours_. (IV. 4.)

LXXII.

_The Idea of_ Polarity _involves the conception of contrary properties in contrary directions:--the properties being, for example, attraction and repulsion, darkness and light, synthesis and analysis; and the contrary directions being those which are directly opposite, or, in some cases, those which are at right angles._ (V. 1.)

LXXIII. (Doubtful.)

_Coexistent polarities are fundamentally identical._ (V. 2.)

LXXIV.

_The Idea of Chemical_ Affinity, _as implied in Elementary Composition, involves peculiar conceptions. It is not properly expressed by assuming the qualities of bodies to_ resemble _those of the elements, or to depend on the_ figure _of the elements, or on their_ attractions. (VI. 1.) {19}

LXXV.

_Attractions take place between bodies, Affinities between the particles of a body. The former may be compared to the alliances of states, the latter to the ties of family._ (VI. 2.)

LXXVI.

_The governing principles of Chemical Affinity are, that it is_ elective; _that it is_ definite; _that it_ determines the properties _of the compound; and that_ analysis is possible. (VI. 2.)

LXXVII.

_We have an idea of_ Substance: _and an axiom involved in this Idea is, that_ the weight of a body is the sum of the weights of all its elements. (VI. 3.)

LXXVIII.

_Hence Imponderable Fluids are not to be admitted as chemical elements._ (VI. 4.)

LXXIX.

_The Doctrine of Atoms is admissible as a mode of expressing and calculating laws of nature; but is not proved by any fact, chemical or physical, as a philosophical truth._ (VI. 5.)

LXXX.

_We have an Idea of_ Symmetry; _and an axiom involved in this Idea is, that in a symmetrical natural body, if there be a tendency to modify any member in any manner, there is a tendency to modify all the corresponding members in the same manner._ (VII. 1.)

LXXXI.

_All hypotheses respecting the manner in which the elements of inorganic bodies are arranged in space, must be constructed with regard to the general facts of crystallization._ (VII. 3.) {20}

LXXXII.

_When we consider any object as_ One, _we give unity to it by an act of thought. The condition which determines what this unity shall include, and what it shall exclude, is this;--that assertions concerning the one thing shall be possible._ (VIII. 1.)

LXXXIII.

_We collect individuals into_ Kinds _by applying to them the Idea of Likeness. Kinds of things are not determined by definitions, but by this condition:--that general assertions concerning such kinds of things shall be possible._ (VIII. 1.)

LXXXIV.

_The_ Names _of kinds of things are governed by their use; and that may be a right name in one use which is not so in another. A whale is not a_ fish _in natural history, but it is a_ fish _in commerce and law._ (VIII. 1.)

LXXXV.

_We take for granted that each kind of things has a special_ character _which may be expressed by a Definition. The ground of our assumption is this;--that reasoning must be possible._ (VIII. 1.)

LXXXVI.

_The "Five Words,"_ Genus, Species, Difference, Property, Accident, _were used by the Aristotelians, in order to express the subordination of Kinds, and to describe the nature of Definitions and Propositions. In modern times, these technical expressions have been more referred to by Natural Historians than by Metaphysicians._ (VIII. 1.)

LXXXVII.

_The construction of a Classificatory Science includes_ Terminology, _the formation of a descriptive language;_--Diataxis, _the Plan of the System of Classification, called_ {21} _also the_ Systematick;--Diagnosis, _the Scheme of the Characters by which the different Classes are known, called also the_ Characteristick. Physiography _is the knowledge which the System is employed to convey. Diataxis includes_ Nomenclature. (VIII. 2.)

LXXXVIII.

Terminology _must be conventional, precise, constant; copious in words, and minute in distinctions, according to the needs of the science. The student must understand the terms,_ directly _according to the convention, not through the medium of explanation or comparison._ (VIII. 2.)

LXXXIX.

_The_ Diataxis,_ or Plan of the System, may aim at a Natural or at an Artificial System. But no classes can be absolutely artificial, for if they were, no assertions could be made concerning them._ (VIII. 2.)

XC.

_An_ Artificial System _is one in which the_ smaller _groups_ (_the Genera_) _are_ natural; _and in which the_ wider _divisions_ (_Classes, Orders_) _are constructed by the_ peremptory _application of selected Characters;_ (_selected, however, so as not to break up the smaller groups._) (VIII. 2.)

XCI.

_A_ Natural System _is one which attempts to make_ all _the divisions_ natural, _the widest as well as the narrowest; and therefore applies_ no _characters_ peremptorily. (VIII. 2.)

XCII.

_Natural Groups are best described, not by any Definition which marks their boundaries, but by a_ Type _which marks their center. The Type of any natural group is an example which possesses in a marked degree all the leading characters of the class._ (VIII. 2.) {22}

XCIII.

_A Natural Group is steadily fixed, though not precisely limited; it is given in position, though not circumscribed; it is determined, not by a boundary without, but by a central point within;--not by what it strictly excludes, but by what it eminently includes;--by a Type, not by a Definition._ (VIII. 2.)

XCIV.

_The prevalence of Mathematics as an element of education has made us think Definition the philosophical mode of fixing the meaning of a word: if_ (_Scientific_) _Natural History were introduced into education, men might become familiar with the fixation of the signification of words by_ Types; _and this process agrees more nearly with the common processes by which words acquire their significations._ (VIII. 2.)

XCV.

_The attempts at Natural Classification are of three sorts; according as they are made by the process of_ blind trial, _of_ general comparison, _or of_ subordination of characters. _The process of Blind Trial professes to make its classes by attention to all the characters, but without proceeding methodically. The process of General Comparison professes to enumerate all the characters, and forms its classes by the_ majority. _Neither of these methods can really be carried into effect. The method of Subordination of Characters considers some characters as_ more important _than others; and this method gives more consistent results than the others. This method, however, does not depend upon the Idea of Likeness only, but introduces the Idea of Organization or Function._ (VIII. 2.)

XCVI.

_A_ Species _is a collection of individuals, which are descended from a common stock, or which resemble such a collection as much as these resemble each other: the resemblance being opposed to a_ definite _difference._ (VIII. 2.) {23}

XCVII.

_A_ Genus _is a collection of species which resemble each other more than they resemble other species: the resemblance being opposed to a_ definite _difference._ (VIII. 2.)

XCVIII.

_The_ Nomenclature _of a Classificatory Science is the collection of the names of the Species, Genera, and other divisions. The_ binary _nomenclature, which denotes a species by the_ generic _and_ specific _name, is now commonly adopted in Natural History._ (VIII. 2.)

XCIX.

_The_ Diagnosis, _or Scheme of the Characters, comes, in the order of philosophy, after the Classification. The characters do not_ make _the classes, they only enable us to_ recognize _them. The Diagnosis is an Artificial Key to a Natural System._ (VIII. 2.)

C.

_The basis of all Natural Systems of Classification is the Idea of Natural Affinity. The Principle which this Idea involves is this:--Natural arrangements, obtained from_ different _sets of characters, must_ coincide _with each other._ (VIII. 4.)

CI.

_In order to obtain a Science of Biology, we must analyse the Idea of Life. It has been proved by the biological speculations of past time, that Organic Life cannot rightly be solved into Mechanical or Chemical Forces, or the operation of a Vital Fluid, or of a Soul._ (IX. 2.)

CII.

_Life is a System of Vital Forces; and the conception of such Forces involves a peculiar Fundamental Idea._ (IX. 3.) {24}

CIII.

_Mechanical, chemical, and vital Forces form an ascending progression, each including the preceding. Chemical Affinity includes in its nature Mechanical Force, and may often be practically resolved into Mechanical Force._ (_Thus the ingredients of gunpowder, liberated from their chemical union, exert great mechanical Force: a galvanic battery acting by chemical process does the like._) _Vital Forces include in their nature both chemical Affinities and mechanical Forces: for Vital Powers produce both chemical changes,_ (_as digestion,_) _and motions which imply considerable mechanical force,_ (_as the motion of the sap and of the blood._) (IX. 4.)

CIV.

_In_ voluntary _motions, Sensations produce Actions, and the connexion is made by means of Ideas: in_ reflected _motions, the connexion neither seems to be nor is made by means of Ideas: in_ instinctive _motions, the connexion is such as requires Ideas, but we cannot believe the Ideas to exist._ (IX. 5.)

CV.

_The Assumption of a Final Cause in the structure of each part of animals and plants is as inevitable as the assumption of an Efficient Cause for every event. The maxim that in organized bodies nothing is_ in vain, _is as necessarily true as the maxim that nothing happens_ by chance. (IX. 6.)

CVI.

_The Idea of living beings as subject to_ disease _includes a recognition of a Final Cause in organization; for disease is a state in which the vital forces do not attain their_ proper ends. (IX. 7.)

CVII.

_The Palætiological Sciences depend upon the Idea of Cause: but the leading conception which they involve is that of_ historical cause, _not mechanical cause._ (X. 1.) {25}

CVIII.

_Each Palætiological Science, when complete, must possess three members: the_ Phenomenology, _the_ Ætiology, _and the_ Theory. (X. 2.)

CIX.

_There are, in the Palætiological Sciences, two antagonist doctrines:_ Catastrophes _and_ Uniformity. _The doctrine of a_ uniform course of nature _is tenable only when we extend the nation of Uniformity so far that it shall include Catastrophes._ (X. 3.)

CX.

_The Catastrophist constructs Theories, the Uniformitarian demolishes them. The former adduces evidence of an Origin, the latter explains the evidence away. The Catastrophist's dogmatism is undermined by the Uniformitarian's skeptical hypotheses. But when these hypotheses are asserted dogmatically they cease to be consistent with the doctrine of Uniformity._ (X. 3.)

CXI.

_In each of the Palætiological Sciences, we can ascend to remote periods by a chain of causes, but in none can we ascend to a_ beginning _of the chain._ (X. 3.)

CXII.

_Since the Palætiological sciences deal with the conceptions of historical cause,_ History, _including_ Tradition, _is an important source of materials for such sciences._ (X. 4.)

CXIII.

_The history and tradition which present to us the providential course of the world form a_ Sacred Narrative; _and in reconciling the Sacred Narrative with the results of science, arise inevitable difficulties which disturb the minds of those who reverence the Sacred Narrative._ (X. 4.) {26}

CXIV.

_The disturbance of reverent minds, arising from scientific views, ceases when such views become familiar, the Sacred Narrative being then interpreted anew in accordance with such views._ (X. 4.)

CXV.

_A new interpretation of the Sacred Narrative, made for the purpose of reconciling it with doctrines of science, should not be insisted on till such doctrines are clearly proved; and when they are so proved, should be frankly accepted, in the confidence that a reverence for the Sacred Narrative is consistent with a reverence for the Truth._ (X. 4.)

CXVI.

_In contemplating the series of causes and effects which constitutes the world, we necessarily assume a_ First Cause _of the whole series._ (X. 5.)

CXVII.

_The Palætiological Sciences point backwards with lines which are broken, but which all converge to the_ same _invisible point: and this point is the Origin of the Moral and Spiritual, as well as of the Natural World._ (X. 5.)

NOVUM ORGANON RENOVATUM.

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