ideas which warps the judgments of the multitude in moral, religious, and political inquiries.

From the facts which have now been stated, it is easy to conceive the manner in which the association of ideas has a tendency to mislead the judgment in the first of the three cases already enumerated. When two subjects of thought are so intimately connected together in the mind, that we find it scarcely possible to consider them apart, it must require no common efforts of attention to conduct any process of reasoning which relates to either. I formerly took notice of the errors to which we are exposed in consequence of the ambiguity of words; and of the necessity of frequently checking and correcting our general reasonings by means of particular examples; but in the cases to which I allude at present, there is (if I may use the expression) an ambiguity of things; so that even when the mind is occupied about particulars, it finds it difficult to separate the proper objects of its attention from others with which it has been long accustomed to blend them. The cases, indeed, in which such obstinate and invincible associations are formed among different subjects of thought, are not very numerous, and occur chiefly in our metaphysical researches ; but in every mind casual combinations of an inferior degree of strength have an habitual effect in disturbing the intellectual powers, and are not to be conquered without persevering exertions, of which few men are capable. The obvious effects which this tendency to combination produces on the judgment, in confounding together those ideas which it is the province of the metaphysician to distinguish, sufficiently illustrate the mode of its operation in those numerous instances in which its influence, though not so complete and striking, is equally real, and far more dangerous.

II. The association of ideas is a source of speculative error, by misleading us in those anticipations of the future from the past, which are the foundation of our conduct in life.

The great object of philosophy, as I have already remarked more than once, is to ascertain the laws which regulate the succession of events, both in the physical and moral worlds; in

order that, when called upon to act in any particular combination of circumstances, we may be enabled to anticipate the probable course of nature from our past experience, and to regulate our conduct accordingly.

As a knowledge of the established connexions among events. is the foundation of sagacity and of skill, both in the practical arts and in the conduct of life, nature has not only given to all men a strong disposition to remark, with attention and curiosity, those phenomena which have been observed to happen nearly at the same time, but has beautifully adapted to the uniformity of her own operations, the laws of association in the human mind. By rendering contiguity in time one of the strongest of our associating principles, she has conjoined together in our thoughts the same events which we have found conjoined in our experience, and has thus accommodated (without any effort on our part) the order of our ideas to that scene in which we are destined to act.

The degree of experience which is necessary for the preservation of our animal existence, is acquired by all men without any particular efforts of study. The laws of nature, which it is most material for us to know, are exposed to the immediate observation of our senses, and establish, by means of the principle of association, a corresponding order in our thoughts, long before the dawn of reason and reflection, or at least long before that period of childhood to which our recollection afterwards extends.

This tendency of the mind to associate together events which have been presented to it nearly at the same time, although on the whole it is attended with infinite advantages, yet, like many other principles of our nature, may occasionally be a source of inconvenience, unless we avail ourselves of our reason and of our experience in keeping it under proper regulation. Among the various phenomena which are continually passing before us, there is a great proportion whose vicinity in time. does not indicate a constancy of conjunction; and unless we be careful to make the distinction between these two classes of connexions, the order of our ideas will be apt to correspond

with the one as well as with the other, and our unenlightened experience of the past will fill the mind, in numberless instances, with vain expectations, or with groundless alarms concerning the future. This disposition to confound together accidental and permanent connexions, is one great source of popular superstitions. Hence the regard which is paid to unlucky days, to unlucky colours, and to the influence of the planets; apprehensions which render human life to many a continued series of absurd terrors. Lucretius compares them to those which children feel, from an idea of the existence of spirits in the dark:

"Ac veluti pueri trepidant, atque omnia cæcis

In tenebris metuunt, sic nos in luce timemus,
Interdum nihilo quæ sunt metuenda magis."

Such spectres can be dispelled by the light of philosophy only, which, by accustoming us to trace established connexions, teaches us to despise those which are casual; and, by giving a proper direction to that bias of the mind which is the foundation of superstition, prevents it from leading us astray.

In the instances which we have now been considering, events come to be combined together in the mind merely from the accidental circumstance of their contiguity in time, at the moment when we perceived them. Such combinations are confined, in a great measure, to uncultivated and unenlightened. minds, or to those individuals who, from nature or education, have a more than ordinary facility of association. But there are other accidental combinations which are apt to lay hold of the most vigorous understandings, and from which, as they are the natural and necessary result of a limited experience, no superiority of intellect is sufficient to preserve a philosopher in the infancy of physical science.

As the connexions among physical events are discovered to us by experience alone, it is evident that, when we see a phenomenon preceded by a number of different circumstances, it is impossible for us to determine, by any reasoning a priori, which of these circumstances are to be regarded as the constant, and

which as the accidental, antecedents of the effect. If, in the course of our experience, the same combination of circumstances is always exhibited to us without any alteration, and is invariably followed by the same result, we must for ever remain ignorant whether this result be connected with the whole combination, or with one or more of the circumstances combined; and therefore, if we are anxious upon any occasion to produce a similar effect, the only rule that we can follow with perfect security, is to imitate in every particular circumstance the combination which we have seen. It is only where we have an opportunity of separating such circumstances from each other, of combining them variously together, and of observing the effects which result from these different experiments, that we can ascertain with precision the general laws of nature, and strip physical causes of their accidental and unessential concomitants.

To illustrate this by an example. Let us suppose that a savage, who, in a particular instance, had found himself relieved of some bodily indisposition by a draught of cold water, is a second time afflicted with a similar disorder, and is desirous to repeat the same remedy. With the limited degree of experience which we have here supposed him to possess, it would be impossible for the acutest philosopher, in his situation, to determine whether the cure was owing to the water which was drunk, to the cup in which it was contained, to the fountain from which it was taken, to the particular day of the month, or to the particular age of the moon. In order, therefore, to insure the success of the remedy, he will very naturally and very wisely copy, as far as he can recollect, every circumstance which accompanied the first application of it. He will make use of the same cup, draw the water from the same fountain, hold his body in the same posture, and turn his face in the same direction; and thus all the accidental circumstances in which the first experiment was made, will come to be associated equally in his mind with the effect produced. The fountain from which the water was drawn will be considered as possessed of particular virtues; and the cup from which it was drunk will

be set apart from vulgar uses, for the sake of those who may afterwards have occasion to apply the remedy. It is the enlargement of experience alone, and not any progress in the art of reasoning, which can cure the mind of these associations, and free the practice of medicine from those superstitious observances with which we always find it encumbered among rude nations.1

Many instances of this species of superstition might be produced from the works of philosophers who have flourished in more enlightened ages. In particular, many might be produced from the writings of those physical inquirers who immediately succeeded to Lord Bacon; and who, convinced by his arguments of the folly of all reasonings a priori concerning the laws of nature, were frequently apt to run into the opposite extreme, by recording every circumstance, even the most ludicrous, and the most obviously inessential, which attended their experiments.2

The observations which have been hitherto made relate entirely to associations founded on casual combinations of material objects or of physical events. The effects which these associations produce on the understanding, and which are so palpable that they cannot fail to strike the most careless observer, will prepare the reader for the remarks I am now to make on some analogous prejudices which warp our opinions on still more important subjects.

As the established laws of the material world, which have been exhibited to our senses from our infancy, gradually accommodate to themselves the order of our thoughts, so the most arbitrary and capricious institutions and customs, by a long and

1

1 [As an illustration of this, it is worth the reader's while to consult the account given in the Natural History of Pliny of the state of medical science among the Druids. A short abstract of it may be found in Dr. Henry's History of Great Britain, vol. ii. pp. 47, 48.]

The reader will scarcely believe that the following cure for a dysentery

is copied verbatim from the works of Mr. Boyle:

"Take the thigh-bone of a hanged man, (perhaps another may serve, but this was still made use of,) calcine it to whiteness, and having purged the patient with an antimonial medicine, give him one drachm of this white powder for one dose, in some good cordial, whe ther conserve or liquor."