it not rather a most groundless presumption? Yet it may be asked, does it not possess all the characteristics of induction, as they have been laid down by some logical writers? For wherein does the case we have supposed, differ from their commonly cited example: "This, that, and the other loadstone, attracts iron,therefore all loadstones do?" Or why is not the former of these instances as good reasoning as the latter?

In the case of the balls, we cannot assign or imagine any reason why one should be white because others are so; any supposable connexion between the circumstance of the balls being together in the bag, and their colour. There is no tendency to fancy or expect it. On the other hand, in the case of the loadstone, having observed the effect, in a few instances, we feel a natural tendency to imagine that the same magnetic property subsists whenever we perceive the same external characteristics. We cannot avoid being persuaded that there is a connexion between that particular darkness of colour, weight, hardness, texture, &c., by which we recognise the mineral, and a magnetic power, though we may be at a loss to explain or assign the ground for it.

Yet the only thing which seems at all to warrant the induction from a limited number of instances, is the reasonableness of such an intuitive persuasion. When, therefore, we have only a limited number of instances, which we can examine (and such is the

case, in fact, in almost all physical inquiries,) no inductive inferences can properly be made, unless we feel assured of some probable ground for expecting a common connexion to subsist between the individual cases. Can we, then, succeed in tracing any probable principle to which the existence of such a persuasion may be traced?-Can we analyse it up to any rational ground of belief? This is a most important point of our inquiry; and to it our attention must next be directed. (See Note A.)

Belief in the Uniformity of Nature.

Now there is one grand, fundamental principle, without which no induction of laws from particular instances, no generalizations of individual truths, no regular or systematic study of nature, could ever proceed: and this is our conviction of a permanence and uniformity in the order of natural things: our belief that that which has happened in succession for days and years past, will, under the same circumstances, continue to happen for time to come: our persuasion that what so takes place in one instance, in one place, will and does take place, under the same conditions, in all other instances, and in all other places. We suppose, that is, that nature is so constituted, that there exists some principle of undeviating regularity in the connexion of qualities and properties, of causes and effects, even though we should fail in always tracing it.

This belief undoubtedly exists and operates in very different degrees in different minds. But a share of it, at least, is so universal, that some metaphysicians have been disposed to regard it as constituting one of the inherent principles of our nature*. Thus, the most ignorant person infers that the sun will rise to-morrow, and for succeeding days and years, because he has so regularly witnessed it before; and that a stone falls to the ground as constantly in America as in Europe.

In the limited form in which we commonly notice the operation of this sort of intuitive persuasion, it certainly does not amount to anything like a philosophical conviction of the uniformity of natural causes. It is, doubtless, restricted to certain isolated classes of facts, which in all their circumstances are constantly falling under the observation. In those limited instances, the individual, perhaps, relies on their recurrence from mere habit, which probably does not produce in his mind any general belief that other events beyond the limits of his observation are regulated by any like constant uniformity. Nor when the idea is suggested is he able to perceive the force of the inference from analogy; but, probably, imagines all things beyond the precise extent of his observation to be destitute of any determinate order, and the course of events in

* Reid and Turgot consider it an ultimate principle of the human mind. Reid calls it specifically "The inductive principle."-Inquiry into Human Mind, ch. vi. § 24.

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general, either under the dominion of arbitrary agency, or abandoned to chance or blind destiny.

In proportion, however, as the mind is more cultivated, and man accustomed to reflect and reason on the objects continually presented to his senses, he is naturally, and even unconsciously, led to enlarge his persuasion of the general recurrence of natural phenomena, in the same order in which he has several times witnessed it. This persuasion easily extends itself to a great variety of particular instances, in which its correctness is soon verified by observation. The same habitual judgment thus gains strength by every hour's experience. The confidence with which the mind calculates, as it were, upon the permanence of a certain order in physical events, increases with rapidly-accumulating force; and the improvement of the faculties by study, and the enlargement of our stores of information from wider observation of physical facts, soon begins to induce the habit of extending our persuasion of the uniformity of natural causes, beyond the mere bounds of familiar phenomena, to those which are placed out of our immediate examination, but which we come naturally to imagine must be regulated by a like constancy.

Founded, then, on the natural constitution of the human mind, confirmed by daily experience, and verified by every advance in the accurate study both of mental and material phenomena, the belief in the existence of this uniformity becomes, in fact,

the basis of all acquisition of knowledge, and enables us, without hesitation, to advance in our conclusions from the known to the unknown, from truths actually before us and within our reach, to those which may be hidden from us, or beyond the limits of sensible experience.

The belief in the uniformity and permanence of natural order, combined with, and perhaps dependent on, the tendency of the human mind to generalize its observations, unite to supply, as it were, at once the first impulse and primary elements of philosophic investigation. But it is further necessary that much care and skill be employed in the direction and use of them before they can produce

any substantial results. We have then further to inquire how this is to be done; and we shall find that the models by which we must be guided, are to be found in the careful and extended study of already established natural relations.

Antecedent Probability in Induction.

THE principles by which we are to be guided in advancing to sound generalizations of observed physical relations, must be those derived from the careful study and comparison of such generalizations previously confirmed in other corresponding instances, which will suggest probabilities antecedent to actual experience.

It will be to little purpose that we are persuaded of the existence of some uniformity in natural laws,