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History Of Scientific Ideas

William Whewell

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HISTORY OF SCIENTIFIC IDEAS.

HISTORY OF SCIENTIFIC IDEAS.

By WILLIAM WHEWELL, D.D., MASTER OF TRINITY COLLEGE, CAMBRIDGE, AND CORRESPONDING MEMBER OF THE INSTITUTE OF FRANCE. BEING THE FIRST PART OF THE PHILOSOPHY OF THE INDUCTIVE SCIENCES. THE THIRD EDITION. IN TWO VOLUMES. ΛΑΜΠΑΔIΑ ΕΧΟΝΤΕΣ ΔIΑΔΩΣΟΥΣIΝ ΑΛΛΗΛΟIΣ VOLUME I. LONDON: JOHN W. PARKER AND SON, WEST STRAND. 1858....

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PREFACE TO THIS EDITION.

PREFACE TO THIS EDITION.

THE Chapters now offered to the Reader were formerly published as a portion of The Philosophy of the Inductive Sciences, founded upon their History : but the nature and subject of these Chapters are more exactly described by the present title, The History of Scientific Ideas . For this part of the work is mainly historical, and was, in fact, collected from the body of scientific literature, at the same time that the History of the Inductive Sciences was so collected. The present work contains th

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INTRODUCTION.

INTRODUCTION.

THE Philosophy of Science , if the phrase were to be understood in the comprehensive sense which most naturally offers itself to our thoughts, would imply nothing less than a complete insight into the essence and conditions of all real knowledge, and an exposition of the best methods for the discovery of new truths. We must narrow and lower this conception, in order to mould it into a form in which we may make it the immediate object of our labours with a good hope of success; yet still it may b

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CHAPTER I. Of the Fundamental Antithesis of Philosophy.

CHAPTER I. Of the Fundamental Antithesis of Philosophy.

IN order that we may do something towards determining the nature and conditions of human knowledge, (which I have already stated as the purpose of this work,) I shall have to refer to an antithesis or opposition, which is familiar and generally recognized, and in which the distinction of the things opposed to each other is commonly considered very clear and plain. I shall have to attempt to make this opposition sharper and stronger than it is usually conceived, and yet to shew that the distincti

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CHAPTER II. Of Technical Terms.

CHAPTER II. Of Technical Terms.

1. I T has already been stated that we gather knowledge from the external world, when we are able to apply, to the facts which we observe, some ideal conception, which gives unity and connexion to multiplied and separate perceptions. We have also shown that our conceptions, thus verified by facts, may themselves be united and connected by a new bond of the same nature; and that man may thus have to pursue his way from truth to truth through a long progression of discoveries, each resting on the

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CHAPTER III. Of Necessary Truths.

CHAPTER III. Of Necessary Truths.

1. E VERY advance in human knowledge consists, as we have seen, in adapting new ideal conceptions to ascertained facts, and thus in superinducing the Form upon the Matter, the active upon the passive processes of our minds. Every such step introduces into our knowledge an additional portion of the ideal element, and of those relations which flow from the nature of Ideas. It is, therefore, important for our purpose to examine more closely this element, and to learn what the relations are which ma

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CHAPTER IV. Of Experience.

CHAPTER IV. Of Experience.

1. I HERE employ the term Experience in a more definite and limited sense than that which it possesses in common usage; for I restrict it to matters belonging to the domain of science. In such cases, the knowledge which we acquire, by means of experience, is of a clear and precise nature; and the passions and feelings and interests, which make the lessons of experience in practical matters so difficult to read aright, no longer disturb and confuse us. We may, therefore, hope, by attending to suc

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CHAPTER V. Of the Grounds of Necessary Truths.

CHAPTER V. Of the Grounds of Necessary Truths.

1. T O the question just stated, I reply, that the necessity and universality of the truths which form a part of our knowledge, are derived from the Fundamental Ideas which those truths involve. These ideas entirely shape and circumscribe our knowledge; they regulate the active operations of our minds, without which our passive sensations do not become knowledge. They govern these operations, according to rules which are not only fixed and permanent, but which may be expressed in plain and defin

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CHAPTER VI. The Fundamental Ideas are not Derived from Experience.

CHAPTER VI. The Fundamental Ideas are not Derived from Experience.

1. B Y the course of speculation contained in the last three Chapters, we are again led to the conclusion which we have already stated, that our knowledge contains an ideal element, and that this element is not derived from experience. For we have seen that there are propositions which are known to be necessarily true; and that such knowledge is not, and cannot be, obtained by mere observation of actual facts. It has been shown, also, that these necessary truths are the results of certain fundam

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CHAPTER VII. Of the Philosophy of the Sciences.

CHAPTER VII. Of the Philosophy of the Sciences.

WE proceed, in the ensuing Books, to the closer examination of a considerable number of those Fundamental Ideas on which the sciences, hitherto most successfully cultivated, are founded. In this task, our objects will be to explain and analyze such Ideas so as to bring into view the Definitions and Axioms, or other forms, in which we may clothe the conditions to which our speculative knowledge is subjected. I shall also try to prove, for some of these Ideas in particular, what has been already u

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CHAPTER I. Of the Pure Sciences.

CHAPTER I. Of the Pure Sciences.

1. A LL external objects and events which we can contemplate are viewed as having relations of Space, Time, and Number; and are subject to the general conditions which these Ideas impose, as well as to the particular laws which belong to each class of objects and occurrences. The special laws of nature, considered under the various aspects which constitute the different sciences, are obtained by a mixed reference to Experience and to the Fundamental Ideas of each science. But besides the science

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CHAPTER II. Of the Idea of Space.

CHAPTER II. Of the Idea of Space.

1. B Y speaking of space as an Idea, I intend to imply, as has already been stated, that the apprehension of objects as existing in space, and of the relations of position, &amp;c., prevailing among them, is not a consequence of experience, but a result of a peculiar constitution and activity of the mind, which is independent of all experience in its origin, though constantly combined with experience in its exercise. That the idea of space is thus independent of experience, has already been

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CHAPTER III. Of some Peculiarities of the Idea of Space.

CHAPTER III. Of some Peculiarities of the Idea of Space.

1. S OME of the Ideas which we shall have to examine involve conceptions of certain relations of objects, as the idea of Cause and of Likeness; and may appear to be suggested by experience, enabling us to abstract this general relation from particular cases. But it will be seen that Space is not such a general conception of a relation. For we do not speak of Spaces as we speak of Causes and Likenesses, but of Space. And when we speak of spaces , we understand by the expression, parts of one and

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CHAPTER IV. Of the Definitions and Axioms which relate to Space.

CHAPTER IV. Of the Definitions and Axioms which relate to Space.

1. T HE relations of space have been apprehended with peculiar distinctness and clearness from the very first unfolding of man’s speculative powers. This was a consequence of the circumstance which we have just noticed, that the simplest of these relations, and those on which the others depend, are seen by intuition. Hence, as soon as men were led to speculate concerning the relations of space, they assumed just principles, and obtained true results. It is said that the science of geometry had i

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CHAPTER V. Of some Objections which have been made to the Doctrines stated in the previous Chapter.3

CHAPTER V. Of some Objections which have been made to the Doctrines stated in the previous Chapter.3

THE Edinburgh Review , No. cxxxv., contains a critique on a work termed The Mechanical Euclid , in which opinions were delivered to nearly the same effect as some of those stated in the last chapter, and hereafter in Chapter xi. Although I believe that there are no arguments used by the reviewer to which the answers will not suggest themselves in the mind of any one who has read with attention what has been said in the preceding chapters (except, perhaps, one or two remarks which have reference

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CHAPTER VI. Of the Perception of Space.

CHAPTER VI. Of the Perception of Space.

1. A CCORDING to the views above explained, certain of the impressions of our senses convey to us the perception of objects as existing in space; inasmuch as by the constitution of our minds we cannot receive those impressions otherwise than in a certain form, involving such a manner of existence. But the question deserves to be asked, What are the impressions of sense by which we thus become acquainted with space and its relations? And as we have seen that this idea of space implies an act of t

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CHAPTER VII. Of the Idea of Time.

CHAPTER VII. Of the Idea of Time.

1. R ESPECTING the Idea of Time, we may make several of the same remarks which we made concerning the idea of space, in order to show that it is not borrowed from experience, but is a bond of connexion among the impressions of sense, derived from a peculiar activity of the mind, and forming a foundation both of our experience and of our speculative knowledge. Time is not a notion obtained by experience. Experience, that is, the impressions of sense and our consciousness of our thoughts, gives us

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CHAPTER VIII. Of some Peculiarities of the Idea of Time.

CHAPTER VIII. Of some Peculiarities of the Idea of Time.

1. T HE Idea of Time, like the Idea of Space, offers to our notice some characters which do not belong to our fundamental ideas generally, but which are deserving of remark. These characters are, in some respects, closely similar with regard to Time and to Space, while, in other respects, the peculiarities of these two ideas are widely different. We shall point out some of these characters. Time is not a general abstract notion collected from experience; as, for example, a certain general concep

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CHAPTER IX. Of the Axioms which relate to Number.

CHAPTER IX. Of the Axioms which relate to Number.

1. T HE foundations of our speculative knowledge of the relations and properties of Number, as well as of Space, are contained in the mode in which we represent to ourselves the magnitudes which are the subjects of our reasonings. To express these foundations in axioms in the case of number, is a matter requiring some consideration, for the same reason as in the case of geometry; that is, because these axioms are principles which we assume as true, without being aware that we have made any assum

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CHAPTER X. Of the Perception of Time and Number.

CHAPTER X. Of the Perception of Time and Number.

1. O UR perception of the passage of time involves a series of acts of memory. This is easily seen and assented to, when large intervals of time and a complex train of occurrences are concerned. But since memory is requisite in order to apprehend time in such cases, we cannot doubt that the same faculty must be concerned in the shortest and simplest cases of succession; for it will hardly be maintained that the process by which we contemplate the progress of time is different, when small, and wh

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CHAPTER XI. Of Mathematical Reasoning.

CHAPTER XI. Of Mathematical Reasoning.

1. Discursive Reasoning. — We have thus seen that our notions of space, time, and their modifications, necessarily involve a certain activity of the mind; and that the conditions of this activity form the foundations of those sciences which have the relations of space, time, and number, for their object. Upon the fundamental principles thus established, the various sciences which are included in the term Pure Mathematics , (Geometry, Algebra, Trigonometry, Conic Sections, and the rest of the Hig

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CHAPTER XII. Of the Foundations of the Higher Mathematics.

CHAPTER XII. Of the Foundations of the Higher Mathematics.

1. The Idea of a Limit. — The general truths concerning relations of space which depend upon the axioms and definitions contained in Euclid’s Elements , and which involve only properties of straight lines and circles, are termed Elementary Geometry: all beyond this belongs to the Higher Geometry. To this latter province appertain, for example, all propositions respecting the lengths of any portions of curve lines; for these cannot be obtained by means of the principles of the Elements alone. Her

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CHAPTER XIII. The Doctrine of Motion.

CHAPTER XIII. The Doctrine of Motion.

1. Pure Mechanism. — The doctrine of Motion, of which we have here to speak, is that in which motion is considered quite independently of its cause, force; for all consideration of force belongs to a class of ideas entirely different from those with which we are here concerned. In this view it may be termed the pure doctrine of motion, since it has to do solely with space and time, which are the subjects of pure mathematics. (See c. i. of this book.) Although the doctrine of motion in connexion

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CHAPTER XIV. Of the Application of Mathematics to the Inductive Sciences.

CHAPTER XIV. Of the Application of Mathematics to the Inductive Sciences.

1. A LL objects in the world which can be made the subjects of our contemplation are subordinate to the conditions of Space, Time, and Number; and on this account, the doctrines of pure mathematics have most numerous and extensive applications in every department of our investigations of nature. And there is a peculiarity in these Ideas, which has caused the mathematical sciences to be, in all cases, the first successful efforts of the awakening speculative powers of nations at the commencement

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CHAPTER I. Of the Mechanical Sciences.

CHAPTER I. Of the Mechanical Sciences.

In the History of the Sciences, that class of which we here speak occupies a conspicuous and important place; coming into notice immediately after those parts of Astronomy which require for their cultivation merely the ideas of space, time, motion, and number. It appears from our History, that certain truths concerning the equilibrium of bodies were established by Archimedes;—that, after a long interval of inactivity, his principles were extended and pursued further in modern times:—and that to

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CHAPTER II. Of the Idea of Cause.

CHAPTER II. Of the Idea of Cause.

1. W E see in the world around us a constant succession of causes and effects connected with each other. The laws of this connexion we learn in a great measure from experience, by observation of the occurrences which present themselves to our notice, succeeding one another. But in doing this, and in attending to this succession of appearances, of which we are aware by means of our senses, we supply from our own minds the Idea of Cause. This Idea, as we have already shown with respect to other Id

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CHAPTER III. Modern Opinions respecting the Idea of Cause.

CHAPTER III. Modern Opinions respecting the Idea of Cause.

1. T OWARDS the end of the seventeenth century there existed in the minds of many of the most vigorous and active speculators of the European literary world, a strong tendency to ascribe the whole of our Knowledge to the teaching of Experience. This tendency, with its consequences, including among them the reaction which was produced when the tenet had been pushed to a length manifestly absurd, has exercised a very powerful influence upon the progress of metaphysical doctrines up to the present

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CHAPTER IV. Of the Axioms which relate to the Idea of Cause.

CHAPTER IV. Of the Axioms which relate to the Idea of Cause.

1. Causes are abstract Conceptions. — We have now to express, as well as we can, the fundamental character of that Idea of Cause of which we have just proved the existence. This may be done, at least for purposes of reasoning, in this as in former instances, by means of axioms. I shall state the principal axioms which belong to this subject, referring the reader to his own thoughts for the axiomatic evidence which belongs to them. But I must first observe, that in order to express general and ab

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CHAPTER V. Of the Origin of our Conceptions of Force and Matter.

CHAPTER V. Of the Origin of our Conceptions of Force and Matter.

1. Force. — When the faculties of observation and thought are developed in man, the idea of causation is applied to those changes which we see and feel in the state of rest and motion of bodies around us. And when our abstract conceptions are thus formed and named, we adopt the term Force , and use it to denote that property which is the cause of motion produced, changed, or prevented. This conception is, it would seem, mainly and primarily suggested by our consciousness of the exertions by whic

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CHAPTER VI. Of the Establishment of the Principles of Statics.

CHAPTER VI. Of the Establishment of the Principles of Statics.

1. Object of the Chapter. — In the present and the succeeding chapters we have to show how the general axioms of Causation enable us to construct the science of Mechanics. We have to consider these axioms as moulding themselves, in the first place, into certain fundamental mechanical principles, which are of evident and necessary truth in virtue of their dependence upon the general axioms of Causation; and thus as forming a foundation for the whole structure of the science;—a system of truths no

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CHAPTER VII. Of the Establishment of the Principles of Dynamics.

CHAPTER VII. Of the Establishment of the Principles of Dynamics.

1. I N the History of Mechanics, I have traced the steps by which the three Laws of Motion and the other principles of mechanics were discovered, established, and extended to the widest generality of form and application. We have, in these laws, examples of principles which were, historically speaking, obtained by reference to experience. Bearing in mind the object and the result of the preceding discussions, we cannot but turn with much interest to examine these portions of science; to inquire

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CHAPTER VIII. Of the Paradox of Universal Propositions obtained from Experience.

CHAPTER VIII. Of the Paradox of Universal Propositions obtained from Experience.

1. I T was formerly stated 38 that experience cannot establish any universal or necessary truths. The number of trials which we can make of any proposition is necessarily limited, and observation alone cannot give us any ground of extending the inference to untried cases. Observed facts have no visible bond of necessary connexion, and no exercise of our senses can enable us to discover such connexion. We can never acquire from a mere observation of facts, the right to assert that a proposition i

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CHAPTER IX. Of the Establishment of the Law of Universal Gravitation.

CHAPTER IX. Of the Establishment of the Law of Universal Gravitation.

THE doctrine of universal gravitation is a feature of so much importance in the history of science that we shall not pass it by without a few remarks on the nature and evidence of the doctrine. 1. To a certain extent the doctrine of the attraction of bodies according to the law of the inverse square of the distance, exhibits in its progress among men the same general features which we have noticed in the history of the laws of motion. This doctrine was maintained à priori on the ground of its si

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CHAPTER X. Of the general Diffusion of clear Mechanical Ideas.

CHAPTER X. Of the general Diffusion of clear Mechanical Ideas.

1. W E have seen how the progress of knowledge upon the subject of motion and force has produced, in the course of the world’s history, a great change in the minds of acute and speculative men; so that such persons can now reason with perfect steadiness and precision upon subjects on which, at first, their thoughts were vague and confused; and can apprehend, as truths of complete certainty and evidence, laws which it required great labour and time to discover. This complete development and clear

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CHAPTER I. Of the Idea of a Medium as commonly employed.

CHAPTER I. Of the Idea of a Medium as commonly employed.

1. Of Primary and Secondary Qualities. — In the same way in which the mechanical sciences depend upon the Idea of Cause, and have their principles regulated by the development of that Idea, it will be found that the sciences which have for their subject Sound, Light, and Heat, depend for their principles upon the Fundamental Idea of Media by means of which we perceive those qualities. Like the idea of cause, this idea of a medium is unavoidably employed, more or less distinctly, in the common, u

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CHAPTER II. On Peculiarities in the Perceptions of the Different Senses.

CHAPTER II. On Peculiarities in the Perceptions of the Different Senses.

1. W E cannot doubt that we perceive all secondary qualities by means of immediate impressions made, through the proper medium of sensation, upon our organs. Hence all the senses are sometimes vaguely spoken of as modifications of the sense of feeling. It will, however, be seen, on reflection, that this mode of speaking identifies in words things which in our conceptions have nothing in common. No impression on the organs of touch can be conceived as having any resemblance to colour or smell. No

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CHAPTER III. Successive Attempts at the Scientific Application of the Idea of a Medium.

CHAPTER III. Successive Attempts at the Scientific Application of the Idea of a Medium.

1. I N what precedes, we have shown by various considerations that we necessarily and universally assume the perception of secondary qualities to take place by means of a medium interjacent between the object and the person perceiving. Perception is affected by various peculiarities, according to the nature of the quality perceived: but in all cases a medium is equally essential to the process. This principle, which, as we have seen, is accepted as evident by the common understanding of mankind,

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CHAPTER IV. Of the Measure of Secondary Qualities.

CHAPTER IV. Of the Measure of Secondary Qualities.

THE ultimate object of our investigation in each of the Secondary Mechanical Sciences, is the nature of the processes by which the special impressions of sound, light, and heat, are conveyed, and the modifications of which these processes are susceptible. And of this investigation, as we have seen, the necessary basis is the principle, that these impressions are transmitted by means of a medium. But before we arrive at this ultimate object, we may find it necessary to occupy ourselves with sever

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CHAPTER I. Attempts at the Scientific Application of the Idea of Polarity.

CHAPTER I. Attempts at the Scientific Application of the Idea of Polarity.

1. I N some of the mechanical sciences, as Magnetism and Optics, the phenomena are found to depend upon position (the position of the magnet, or of the ray of light,) in a peculiar alternate manner. This dependence, as it was first apprehended, was represented by means of certain conceptions of space and force, as for instance by considering the two Poles of a magnet. But in all such modes of representing these alternations by the conceptions borrowed from other ideas, a closer examination detec

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CHAPTER II. Of the Connexion of Polarities.

CHAPTER II. Of the Connexion of Polarities.

1. I T has appeared in the preceding chapter that in cases in which the phenomena suggest to us the idea of Polarity, we are also led to assume some material machinery as the mode in which the polar forces are exerted. We assume, for instance, globular particles which possess poles, or the vibrations of a fluid, or two fluids attracting each other; in every case, in short, some hypothesis by which the existence and operation of the Polarity is embodied in geometrical and mechanical properties of

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CHAPTER I. Attempts to conceive Elementary Composition.

CHAPTER I. Attempts to conceive Elementary Composition.

1. W E have now to bring into view, if possible, the Ideas and General Principles which are involved in Chemistry,—the science of the composition of bodies. For in this as in other parts of human knowledge, we shall find that there are certain Ideas, deeply seated in the mind, though shaped and unfolded by external observation, which are necessary conditions of the existence of such a science. These Ideas it is, which impel man to such a knowledge of the Composition of bodies, which give meaning

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CHAPTER II. Establishment and Development of the Idea of Chemical Affinity.

CHAPTER II. Establishment and Development of the Idea of Chemical Affinity.

1. T HE earlier chemists did not commonly involve themselves in the confusion into which the mechanical philosophers ran, of comparing chemical to mechanical forces. Their attention was engaged, and their ideas were moulded, by their own pursuits. They saw that the connexion of elements and compounds with which they had to deal, was a peculiar relation which must be studied directly; and which must be understood, if understood at all, in itself, and not by comparison with a different class of re

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CHAPTER III. Of the Idea of Substance.

CHAPTER III. Of the Idea of Substance.

1. Axiom of the Indestructibility of Substance. — We now come to an Idea of which the history is very different from those of which we have lately been speaking. Instead of being gradually and recently brought into a clear light, as has been the case with the Ideas of Polarity and Affinity, the Idea of Substance has been entertained in a distinct form from the first periods of European speculation. That this is so, is proved by our finding a principle depending upon this Idea current as an axiom

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NOTE TO CHAPTER III.

NOTE TO CHAPTER III.

[3rd Ed.]—[ The doctrine here propounded, that All Matter is Heavy, has been opposed by Sir William Hamilton of Edinburgh. ( Works of Reid , note, p. 853.) This writer is a man of unquestionable acuteness and of very extensive reading; but his acuteness shows itself in barren ontological distinctions, which appear to me to be of the same character as the speculations of the eminent Schoolmen of the most sterile periods of the dark ages. That he should have no conception of progressive or inducti

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CHAPTER IV. Application of the Idea of Substance in Chemistry.

CHAPTER IV. Application of the Idea of Substance in Chemistry.

1. A Body is Equal to the Sum of its Elements. — From the earliest periods of chemistry the balance has been familiarly used to determine the proportions of the ingredients and of the compound; and soon after the middle of the last century, this practice was so studiously followed, that Wenzel and Richter were thereby led to the doctrine of Definite Proportions. But yet the full value and significance of the balance, as an indispensable instrument in chemical researches, was not understood till

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CHAPTER V. The Atomic Theory.

CHAPTER V. The Atomic Theory.

1. The Atomic Theory considered on Chemical Grounds. — We have already seen that the combinations which result from chemical affinity are definite, a certain quantity of one ingredient uniting, not with an uncertain, but with a certain quantity of another ingredient. But it was found, in addition to this principle, that one ingredient would often unite with another in different proportions, and that, in such cases, these proportions are multiples one of another. In the three salts formed by pota

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CHAPTER I. Explication of the Idea of Symmetry.

CHAPTER I. Explication of the Idea of Symmetry.

1. W E have seen in the History of the Sciences, that the principle which I have there termed 1 the Principle of Developed and Metamorphosed Symmetry, has been extensively applied in botany and physiology, and has given rise to a province of science termed Morphology. In order to understand clearly this principle, it is necessary to obtain a clear idea of the Symmetry of which we thus speak. But this Idea of Symmetry is applicable in the inorganic, as well as in the organic kingdoms of nature; i

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CHAPTER II. Application of the Idea of Symmetry to Crystals.

CHAPTER II. Application of the Idea of Symmetry to Crystals.

1. M INERALS and other bodies of definite chemical composition often exhibit that marked regularity of form and structure which we designate by terming them Crystals ; and in such crystals, when we duly study them, we perceive the various kinds of symmetry of which we have spoken in the previous chapter. And the different kinds of symmetry which we have there described are now usually distinguished from each other, by writers on crystallography. Indeed it is mainly to such writers that we are in

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CHAPTER III. Speculations founded upon the Symmetry of Crystals.

CHAPTER III. Speculations founded upon the Symmetry of Crystals.

1. W HEN a crystal, as, for instance, a crystal of Galena, (sulphuret of lead,) is readily divisible into smaller cubes, and these into smaller ones, and so on without limit, it is very natural to represent to ourselves the original cube as really consisting of small cubical elements; and to imagine that it is a philosophical account of the physical structure of such a substance to say that it is made up of cubical molecules. And when the Galena crystal has externally the form of a cube, there i

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CHAPTER I. The Idea of Likeness as Governing the Use of Common Names.

CHAPTER I. The Idea of Likeness as Governing the Use of Common Names.

1. Object of the Chapter. — Not only the Classificatory Sciences, but the application of names to things in the rudest and most unscientific manner, depends upon our apprehending them as like each other. We must therefore endeavour to trace the influence and operation of the Idea of Likeness in the common use of language, before we speak of the conditions under which it acquires its utmost exactness and efficacy. It will be my object to show in this, as in previous cases, that the impressions of

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CHAPTER II. The Methods of Natural History, as regulated by the Idea of Likeness.

CHAPTER II. The Methods of Natural History, as regulated by the Idea of Likeness.

1. Idea of Likeness in Natural History. — The various branches of Natural History, in so far as they are classificatory sciences merely, and do not depend upon physiological views, rest upon the same Idea of Likeness which is the ground of the application of the names, more or less general, of common language. But the nature of science requires that, for her purposes, this Idea should be applied in a more exact and rigourous manner than in its common and popular employment; just as occurs with r

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CHAPTER III. Application of the Natural History Method to Mineralogy.

CHAPTER III. Application of the Natural History Method to Mineralogy.

1. T HE philosophy of the Sciences of Classification has had great light thrown upon it by discussions concerning the methods which are used in Botany: for that science is one of the most complete examples which can be conceived of the consistent and successful application of the principles and ideas of Classification; and this application has been made in general without giving rise to any very startling paradoxes, or disclosing any insurmountable difficulties. But the discussions concerning me

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CHAPTER IV. Of the Idea of Natural Affinity.

CHAPTER IV. Of the Idea of Natural Affinity.

1. I N the Second Chapter of this Book it was shown that although the Classificatory Sciences proceed ostensibly upon the Idea of Resemblance as their main foundation, they necessarily take for granted in the course of their progress a further Idea of Natural Affinity. This appeared 79 by a general consideration of the nature of Science, by the recognition of natural species and genera, even in Artificial Systems of Classification 80 , and by the attempts of botanists to form a Natural System. I

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CHAPTER I. Analogy of Biology With Other Sciences.

CHAPTER I. Analogy of Biology With Other Sciences.

1. I N the History of the Sciences, after treating of the Sciences of Classification, we proceeded to what are there termed the Organical Sciences, including in this term Physiology and Comparative Anatomy. A peculiar feature in this group of sciences is that they involve the notion of living things. The notion of Life , however vague and obscure it may be in men’s minds, is apprehended as a peculiar Idea, not resolvable into any other Ideas, such, for instance, as Matter and Motion. The separat

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CHAPTER II. Successive Biological Hypotheses.

CHAPTER II. Successive Biological Hypotheses.

IN order to abbreviate as much as can conveniently be done the historical view which I have now to take, I shall altogether pass over the physiological speculations of the ancients, and begin my survey with the general revival of science in modern times. We need not dwell long on the fantastical and unsubstantial doctrines concerning physiology which prevailed in the sixteenth century, and which flowed in a great measure from the fertile but ill-regulated imaginations of the cultivators of Alche

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CHAPTER III. Attempts to Analyse the Idea of Life.

CHAPTER III. Attempts to Analyse the Idea of Life.

1. Definitions of Life. — We have seen in the preceding chapter that all attempts to obtain a distinct conception of the nature of Life in general have ended in failure, and produced nothing beyond a negative result. And the conjecture may now naturally occur, that the cause of this failure resides in an erroneous mode of propounding to ourselves the problem. Instead of contemplating Life as a single Idea, it may perhaps be proper to separate it into several component notions: instead of seeking

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CHAPTER IV. Attempts to form Ideas of separate Vital Forces, and first of Assimilation and Secretion.

CHAPTER IV. Attempts to form Ideas of separate Vital Forces, and first of Assimilation and Secretion.

1. I T is to be observed that at present I do not speak of the progress of our knowledge with regard to the detail of the processes which take place in the human body, but of the approach made to some distinct Idea of the specially vital part of each process. In the History of Physiology, it has been seen 72 that all the great discoveries made respecting the organs and motions of the animal frame have been followed by speculations and hypotheses connected with such discoveries. The discovery of

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CHAPTER V. Attempts to form Ideas of separate Vital Forces, continued.—Voluntary Motion.

CHAPTER V. Attempts to form Ideas of separate Vital Forces, continued.—Voluntary Motion.

1. W E formerly noticed the distinctions of organic and animal functions, organic and animal forces, as one of the most marked distinctions to which physiologists have been led in their analysis of the vital powers. I have now taken one of the former, the organic class of functions, namely, Nutrition; and have endeavoured to point out in some measure the peculiar nature of the vital forces by which this function is carried on. It may serve to show the extent and the difficulty of this subject, i

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CHAPTER VI. Of the Idea of Final Causes.

CHAPTER VI. Of the Idea of Final Causes.

1. B Y an examination of those notions which enter into all our reasonings and judgments on living things, it appeared that we conceive animal life as a vortex or cycle of moving matter in which the form of the vortex determines the motions, and these motions again support the form of the vortex: the stationary parts circulate the fluids, and the fluids nourish the permanent parts. Each portion ministers to the others, each depends upon the other. The parts make up the whole, but the existence o

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CHAPTER I. Of Palætiological Sciences in General.

CHAPTER I. Of Palætiological Sciences in General.

1. I HAVE already stated in the History of the Sciences 1 , that the class of Sciences which I designate as Palætiological are those in which the object is to ascend from the present state of things to a more ancient condition, from which the present is derived by intelligible causes. As conspicuous examples of this class we may take Geology, Glossology or Comparative Philology, and Comparative Archæology. These provinces of knowledge might perhaps be intelligibly described as Histories ; the Hi

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CHAPTER II. Of the Three Members of a Palætiological Science.

CHAPTER II. Of the Three Members of a Palætiological Science.

1. Divisions of such Sciences. — In each of the Sciences of this class we consider some particular order of phenomena now existing:—from our knowledge of the causes of change among such phenomena, we endeavour to infer the causes which have made this order of things what it is:—we ascend in this manner to some previous stage of such phenomena;—and from that, by a similar course of inference, to a still earlier stage, and to its causes. Hence it will be seen that each such science will consist of

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CHAPTER III. Of the Doctrine of Catastrophes and the Doctrine of Uniformity.

CHAPTER III. Of the Doctrine of Catastrophes and the Doctrine of Uniformity.

1. Doctrine of Catastrophes. — I have already shown, in the History of Geology, that the attempts to frame a theory of the earth have brought into view two completely opposite opinions:—one, which represents the course of nature as uniform through all ages, the causes which produce change having had the same intensity in former times which they have at the present day;—the other opinion, which sees, in the present condition of things, evidences of catastrophes ;—changes of a more sweeping kind,

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CHAPTER IV. Of the Relation of Tradition to Palætiology.

CHAPTER IV. Of the Relation of Tradition to Palætiology.

1. Importance of Tradition. — Since the Palætiological Sciences have it for their business to study the train of past events produced by natural causes down to the present time, the knowledge concerning such events which is supplied by the remembrance and records of man, in whatever form, must have an important bearing upon these sciences. All changes in the condition and extent of land and sea, which have taken place within man’s observation, all effects of deluges, sea-waves, rivers, springs,

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CHAPTER V. Of the Conception of a First Cause.

CHAPTER V. Of the Conception of a First Cause.

1. A T the end of the last chapter but one, we were led to this result,—that we cannot, in any of the Palætiological Sciences, ascend to a beginning which is of the same nature as the existing cause of events, and which depends upon causes that are still in operation. Philosophers never have demonstrated, and probably never will be able to demonstrate, what was the original condition of the solar system, of the earth, of the vegetable and animal worlds, of languages, of arts. On all these subjec

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