ESSAYS ON THE PURSUIT OF TRUTH.*

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We have denied ourselves the pleasure of a more extended notice of the first two Essays, from a desire to enlarge upon the contents of the third, (on the Uniformity of Causation,) which forms by far the most important portion of the volume, as the positions it is intended to establish induce more momentous consequences than almost any others in the whole range of human inquiry. It contains little that is new; but the abstruse questions which formerly were debated among the learned alone are here presented in a manner likely to engage the attention of many who have hitherto been strangers to their attraction. As the influence of this Essay may therefore be powerful and extensive, it is of considerable consequence whether its reasonings are sound, and its conclusions just. If not, the time will be well bestowed which is employed in exposing their fallacy.

The two principal questions, to the elucidation of which our author's reasonings tend, are the doctrine of Philosophical Necessity, and the determination of the legitimate bounds of Testimony.

The first chapter is "On the Assumption implied in all our Expectations, that like Causes will produce like Effects, or of the future Uniformity of Causation."

The first declaration that we meet with is, that the belief in the uniformity of causation is an instinctive principle. We doubt it. Have we any belief in the connexion of

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Essays on the Pursuit of Truth, the Progress of Knowledge, and on the Fundamental Principle of all Evidence and Expectation. By the Author of "Essays on the Formation and Publication of Opinions." London: Hunter. 1829.

cause and effect antecedent to experiment? And if the idea of such connexion is only suggested by experience, is not the principle of Association, which is at the same time the agent in a multitude of other processes, sufficient to account for the belief? "A burned child dreads the fire," not from an instinctive belief that fire always burns, but because the pain of the burn is associated in his mind with the sight of the fire. If he were assured that the same fire which hurts him would not burn his nurse, he would be less incredulous on the subject than his nurse would be, if a similar assurance was made to her and she, again, might be more easily induced to credit so extraordinary a declaration than the philosopher who understands the theory of combustion. Such degrees of persuasion, we conceive, could not exist, were the minds of these three persons actuated by an instinctive principle. It is unphilosophical to multiply principles unnecessarily; and it appears to us that the belief in question is generated by association. All the circumstances of life tend so strongly to confirm it, that a very short experience is sufficient to establish it too firmly to be overthrown; and the assumption of the uniformity of eausation becomes the basis of all action, the essential principle of all expectation.

The author carefully points out to his readers the distinction between the physical truth that the same causes produce the same effects, and the mental fact that we assume, or take for granted, this uniformity in the operation of causes. In speaking of the former, he uses the phrase Uniformity of Causation the latter, he terms an assumption of the uniformity of causation. We prefer the term Uniformity of Causation to that of Necessary Connexion, because our ignorance of the nature of the connexion forbids us to term it necessary or inevitable. Of the essences of sub

stances we have no knowledge, and can form no conception ;

and our acquaintance with their qualities extends no further than the fact of their mutual operation. Their mode of operation is still concealed from us, and while this is the case, we can with no propriety speak of the necessary connexion of causes and effects. Were the nature of the connexion ascertained by us, we might be able to pronounce on the cause of an unprecedented phenomenon, antecedent to experiment; which it is well known is beyond our power. A gardener on the coast of Jersey was surprised to find, one year, that four or five strawberry plants bore fruit of a larger size and finer flavor than had ever been seen in the island, while their neighbours of the same bed were of the ordinary size. In order to account for the appearance, the gardener, who was a sensible man, examined the soil, and endeavoured to remember whether any peculiar mode of culture had been employed on the plants. Unable to detect the cause by reflection, he tried experiments, adding various ingredients to the soil; first one, then another, then a compound of several; but without success. At length he consulted his assistant, and discovered, on inquiry, that his children had deposited bunches of seaweed on the spot where the plants grew. More sea-weed was applied with good effect, and from that time the strawberry beds were annually manured with its ashes; the gardener having had sufficient experience of its efficacy to believe that his trouble would not be in vain; though his total ignorance of the mode in which the sea-weed operated on the fibres and juices of the plants would have made him hesitate (had he been a metaphysican) to declare that its influence was necessary. Our author, while he adopts the term we prefer, appears to assume the truth of that which we reject believing the uniformity of causation, and necessary connexion of cause and effect, to be interchangeable terms. In this part of the Essay, he avoids the use of the term neces

sary, while he assumes the truth of the signification we ascribe to it. This assumption is consistent with his belief in the instinctive nature of the principle which forms the ground of his argument; but it seems to us to be erroneous.

In the second chapter, the writer points out the fact, (of considerable importance to his object,) that while philosophers have been engaged in laying down the belief of the uniformity of causation as a ground for future expectation, they have neglected the consideration that it applies as well to the past as to the future; and have forgotten to argue that like causes not only will produce, but have produced, like effects.

If the necessary connexion of causes and effects be allowed, and if we admit our belief of this connexion to be instinctive, no proof of the above position is needed. But if not, if the connexion be only uniform, it is obvious that the author is already begging the question which he designs afterwards. to present to his readers. From instinct there is no appeal ; but how is experience to assure us that like causes have always produced like effects? The author affirms with us that it cannot. It is necessary here to make an extract.

"This assumption of the past uniformity of causation will be apparent on the slightest reflection. To have recourse again to our instance of throwing paper into the fire: it is obvious that I not only expect the paper to be burnt, but I assume that fire has always possessed the property of consuming that substance. As a proof that this assumption is involved in my thoughts, it is only necessary to trace the process of my mind in rejecting a narration at variance with my own experience. Should any one assert, that, at a former period of his life, he had thrown paper into the fire, suffered it to remain for five minutes in the flames, and then taken it out unscorched and unconsumed, I should instantly regard the relation as false, and should think it a sufficient refutation to throw a piece of paper into the fire, and thus prove to the narrator the impossibility of what he had asserted. But