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as are connected with the theory of our intellectual faculties. In this point of view, the author has left much to be supplied by his successors; the bent of his own genius having fortunately determined him rather to seize, by a sort of intuitive penetration, great practical results, than to indulge a comparatively sterile curiosity, by remounting to the first sources of experimental knowledge in the principles and laws of the human frame. It is to this humbler task that I propose to confine myself in the sequel. To follow him through the details of his Method, would be inconsistent with the nature of my present undertaking.

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Mistakes of the Ancients concerning the proper object of Philosophy.-Ideas of Bacon on the same subject.-Inductive Reasoning.-Analysis and Synthesis.-Essential dif ference between Legitimate aud Hypothetical Theories.


HAVE had occasion to observe more than once, in the course of the foregoing speculations, that the object of physical science is not to trace necessary connexions, but to ascertain constant conjunctions; not to investigate the nature of those efficient causes on which the phenomena of the universe ultimately depend, but to examine with accuracy what the phenomena are, and what the general laws by which they are regulated.

In order to save repetitions, I here beg leave to refer to some observations on this subject in the first volume. I request more particularly the reader's attention to what I have said, in the second section of the first chapter, on the distinction between physical and efficient causes; and on the origin of that bias of the imagination which leads us to confound them under one common name. That, when we see two events constantly conjoined as antecedent and consequent, our natural apprehensions dispose us to associate the idea of causation or efficiency with the former, and to ascribe to it that power or energy by which the change was produced, is a fact obvious and unquestionable; and hence it is, that in all languages, the avy series of physical causes and effects is metaphorically likened to a scial cause chain, the which are supposed to cessarily connected. The slightest reflection, at the same time, effects like must satisfy us that these apprehensions are inconsistent, and even


and ne

wid to a chain

absurd; our knowledge of physical events reaching no farther than to the laws which regulate their succession; and the words power and energy expressing attributes not of matter but of mind. It is by a natural bias or association somewhat similar, (as I have remarked in the section above mentioned) that we connect our sensations of colour with the primary qualities of body.*

Cause sup


This idea of the object of physical science (which may be justly regarded as the ground-work of Bacon's Novum Organon) differs essentially from that which was entertained by the ancients; according to whom "Philosophy is the science of causes." If, indeed by causes they had meant merely the constant forerunners or antecedents of events, the definition would have coincided nearly with the statement which I have given. But it is evident, that by causes they meant such antecedents as were necessarily connected with the posed by y effects, and from a knowledge of which the effects might be fore- ancient to seen and demonstrated: And it was owing to this confusion between the proper objects of physics and of metaphysics, that, neglecting the observation of facts exposed to the examination of their senses, Javy conneo. they vainly attempted, by synthetical reasoning, to deduce, as ne-tion cessary consequences from their supposed causes, the phenomena and laws of nature.-"(1) Causa ea est," says Cicero, 66 quae id efficit "cujus est causa. Non sic causa intelligi debet, ut quod cuique "antecedat, id ei causa sit; sed quod cuique efficienter antecedat."Itaque dicebat Carneades ne Apollinem quidem posse dicere futu66 ra, nisi ea, quorum causas natura ita contineret, ut ea fieri neces"se esset. Causis enim efficientibus quamque rem cognitis, posse "denique sciri quid futurum esset.†



*Were it not for this bias of the imagination to identify efficient with physical causes, the attention would be continually diverted from the necessary business of life, and the useful exercise of our faculties suspended, in a fruitless astonishment at that hidden ma⚫ chinery, over which nature has drawn an impenetrable veil. To prevent this inconven ient distraction of thought, a farther provision is made in that gradual and impercep tible process by which the changes in the state of the Universe are, in general, accomplished. If an animal or a vegetable were brought into being before our eyes, in an instant of time,-the event would not be in itself more wonderful than their slow growth to maturity from an embryo, or from a seed. But, on the former supposition, there is no man who would not perceive and acknowledge the immediate agency of an intelli gent cause; whereas, according to the actual order of things, the effect steals so insen sibly on the observation, that it excites little or no curiosity, excepting in those who possess a sufficient degree of reflection to contrast the present state of the objects around them, with their first origin, and with the progressive stages of their existence.

+De Fato, 48, 49. The language of Aristotle is equally explicit. ExoTaodai Se οιόμεθα ἕκαστον ἁπλως, αλλα μη τον σοφιστικών τροπον, τον κατα συμβεβηκος, όταν την τ' αιτίαν οιώμεθα γινωσκειν, δι' ἣν το πραγμα ἐστιν, ότι εκείνου αιτία εστί, και μη ενδέχεται τούτ' αλλως έχειν. Sciri autem putamus unamquamque rem simpliciter non

(1) De Fato, 14, 15. (Boston edit. Vol. XVI. p. 168, 169) [The cause that, which produces that of which it is the cause. Cause ought not to be understood of that, which precedes that of which it is the cause; but of that which efficiently precedes it. Therefore Carneades said, that not even Apollo could foretel fu ture events, unless such whose causes are so contained in nature, that they must necessarily happen. For when the efficient cause of any thing is known, we can then know what will take place.]


From this disposition to confound efficient with physical causes, The disposi may be traced the greater part of the theories recorded in the tion to blend history of philosophy. It is this which has given rise to the atefficient with tempts, both in ancient and modern times, to account for all the phenomena of moving bodies by means of impulse, and it is this Shynial al-o which has suggested the simpler expedient of explaining them сащи So by the agency of minds united with the particles of matter. As nise to many the communication of motion by apparent impulse, and our own Theovin. power to produce motion by a volition of the mind, are two facts, of which, from our earliest infancy, we have every moment had experience; we are apt to fancy that we understand perfectly the nexus by which cause and effect are here necessarily conjoined;

sophistico modo, id est ex accidenti, cum putamus causam cognoscere propter quam res est, ejus rei causam esse, nec posse eam aliter se habere.Analyt Poster. Lib i. cap.2.

Nothing, however, can place in so strong a light Aristotle's idea of the connexion between physical causes and effects, as the analogy which he conceived it to bear to the connexion between the links of a mathematical chain of reasoning. Nor is this mode of speaking abandoned by his modern followers. "To deny a first cause (says Dr. Gillies) is to deny all causation: to deny axioms, is for the same reason, to deny all demon. stration." (Vol. f. p. 108.) And in another passage: "We know a mathematical pro position, when we know the causes that make it true. In demonstration, the premises are the causes of the conclusion, and therefore prior to it. We cannot, therefore, de monstrate things in a circle, supporting the premises by the conclusion; because this would be to suppose that the one proposition could be both prior and posterior to the other." (Ibid. p. 96.) Can one mathematical theorem be said to be prior to another in any other sense, than in respect of the order in which they are first presented to our knowledge?

*See Philosophy of the Human Mind, Vol. 1. Chap. i. sect. 2.

With respect to the connexion between impulse and motion, I have the misfortune to differ from my very learned and highly respected friend M Prévost of Geneva; whose opinions on this point may be collected from the two following sentences. "La cause diffère du simple signe précurseur, par sa force, ou son energie productive.-L'im pulsion est un phénomène si commun, soumis à des lois si bien discutées, et si univer. selles, que toute cause qui s'y réduit semble former une classe éminente, et mériter seule le nom d' Agent." (Essais de Philosophie, Tome II. pp. 174, 175.)

I have read with great attention all that M. Prévost has so ingeniously urged in vin dication of the theory of his illustrious countryman Le Sage; but without experiencing that conviction which I have in general received from his reasonings. The arguments of Locke and Hume on the other side of the question appear to my judgment, the long er I reflect on them, the more irresistible; not to mention the powerful support which they derive from the subsequent speculations of Boscovich. (See Locke's Essay, B. II. chap. 23 28 29. and Hume's Essay on Necessary Connexion, Part 1)

In employing the word misfortune, on this occasion, I have no wish to pay an un meaning compliment; but merely to express the painful diffidence which I always feel in my own conclusions, when they happen to be at variance with those of a writer equally distinguished by the depth and by the candour of his philosophical researches.

For some additional illustrations of M. Prévost's opinion on this subject, see Appendix,

To this last class of theories may also be referred the explanations of physical phe nomena by such causes as sympathies, antipathies, Nature's horrour of a void, &c. and other phrases borrowed by analogy from the attributes of animated beings.

[We believe that any thing may be known simply, not sophistically, from circumstances, when we think we know that the cause, on account of which it exists, is the cause of that thing; and that it cannot have any other.]

[Cause differs from the simple preceding sign, by its own force or productive energy. Impulse is a phenomenon so common, subject to laws so well ascertained, and so univer sal, that every one which is reduced to these, appears to form a distinct class, and alone merits the name of Agent.]







The The suppose

and it requires a good deal of reflection to satisfy us that, in both
cases, we are as completely in the dark, as in our guesses concern-
ing the ultimate causes of magnetism or of gravitation.
dreams of the Pythagorean school, with respect to analogies or har- analogy bet
monies between the constitution of the universe, and the mathe-
4 constituti
matical properties of figures and of numbers, were suggested by univer
the same idea of necessary connexions existing among physical oper
phenomena, analogous to those which link together the theorems
My gropert
of geometry or of arithmetic; and by the same fruitless hope of of fignum
penetrating, by abstract and synthetical reasoning, into the myste- suggested by

* Analysis of Aristotle's Logic. Chap. ii. sect. 3.

+ Nat. Auscult. Lib. ii. cap. 7.

Ancient Metaphysics, passim.-The censure bestowed on Aristotle's Physics, by the authors of the French Treatise of Logic, entitled L'Art de Penser, is judicious and dis criminating. "Le principal défaut qu'on y peut trouver, n'est pas qu'elle soit fausse, mais c'est au contraire qu'elle est trop vraie, et qu'elle ne nous apprend que des choses qu'il est impossible d'ignorer."}

[The principal fault we find in it, is not, that it is false, but that it is too true; and
that it teaches us nothing but those things of which it is impossible we should be ignorant.]

In contrasting, as I have now done, the spirit of Bacon's mode of no-philosophizing with that of the ancients, I do not mean to extol his Jacon'sn own notions concerning the relation of cause and effect in physics, as tions of peculiarly correct and consistent. On the contrary, it seems to me evident, that he was led to his logical conclusions, not by any metacaused effect physical analysis of his ideas, but by a conviction, founded on a renot wholly view of the labours of his predecessors, that the plan of inquiry by correct.

which they had been guided must have been erroneous. If he had perceived, as clearly as Barrow, Berkeley, Hume, and many others have done since his time,* that there is not a single instance in which we are able to trace a necessary connexion between two successive events, or to explain in what manner the one follows from the other as an infallible consequence, he would have been naturally led to state his principles in a form far more concise and methodical, and to lay aside much of that scholastic jargon by which his meaning is occasionally obscured. Notwithstanding, however, this vagueness and indistinctness in his language, his comprehensive and penetrating understanding, enlightened by a discriminating survey + of the fruitless inquiries of former ages, enabled him to describe, in the strongest and happiest terms, the nature, the object, and the Most val- limits of philosophical investigation. The most valuable part of his works, at the same time, consists, perhaps, in his reflections on uable part the errours of his predecessors; and on the various causes which of his works have retarded the progress of the sciences and the improvement of the human mind. That he should have executed, with complete success, a system of logical precepts for the prosecution of experimental inquiries, at a period when these were, for the first time, beginning to engage the attention of the curious, was altogether impossible; and yet in his attempt towards this undertaking, he has displayed a reach of thought and a justness of anticipation, which,


In alluding to the relation between cause and effect, Bacon sometimes indulges his fancy in adopting metaphorical and popular expressions. Namque in limine Philosophiae, cum secundae causae, tanquam sensibus proximae, ingerant se menti humanae, mens que ipsa in illis haereat, atque commoretur, oblivio primae causae obrepere possit. Sin quis ulterius pergat, causarumque dependentiam, seriem, et concatenationem, atque opera providentiae intueatur, tune secundum poetarum mythologiam, facile credet, summum naturalis catenae annulum pedi solii Jovis affigi." (De Aug. Scient. Lib. i.) This is very nearly the language of Seneca. "Cum fatom nihil aliud sit quam series implexa causarum, illa est prima omnium causa ex quâ ceterae pendent."‡


In other instances, he speaks (and, in my opinion, much more philosophically) of the opus quod operatur Deus a primordio usque ad finem;" a branch of knowledge which he expressly describes as placed beyond the examination of the human faculties. But this speculation, although the most interesting that can employ our thoughts, bas no imme diate connexion with the logic of physical science.-See note (N.)

[For at the threshold of philosophy, when second causes, perceptible by the senses, force themselves upon the mind; and this rests upon and clings to them, an oblivion of the first cause may creep in. But if we go further, and view the dependence, series, and concatenation of causes, and the works of providence, then, according to poetic mythology, we shall easily perceive, that the most elevated ring of the chain of nature is fastened to the foot of the throne of Jove.]

[Since fate is nothing else than an involved series of causes, that is, the first cause of all, from which the rest depend.]

[The work which God works from the beginning to the end of the creation.]

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