"Inductive philosophy," we are told," or "that which proceeds upon the careful observation "of facts, may be applied to two different classes "of phenomena. The first are those that can be "made the subject of proper experiment, where the "substances are actually in our power, and the judg "ment and artifice of the inquirer can be effectually employed to arrange and combine them in such "a way as to disclose their most hidden properties "and relations. The other class of phenomena are "those that occur in substances that are placed al

66

together beyond our reach, the order and succes"sion of which we are generally unable to control, "and as to which we can do little more than collect "and record the laws by which they appear to be go"verned. These substances are not the object of "experiment, but of observation; and the know

66

ledge we may obtain, by carefully watching their "variations, is of a kind that does not directly in"erease the power which we might otherwise have "had over them. It seems evident, however, that "it is principally in the former of these depart"ments, or the strict experimental philosophy, that "those splendid improvements have been made, "which have erected so vast a trophy to the prospec"tive genius of Bacon. The astronomy of Sir "Isaac Newton is no exception to this general re

some skilful hand, in order to bring it within the reach of a more numerous class of readers. I do not know a more acceptable service which any individual could render to philosophy; and the extreme difficulty of the task would render it an undertaking worthy of the greatest talents.

mark; all that mere observation could do to de"termine the movements of the heavenly bodies, "had been accomplished by the star-gazers who

preceded him; and the law of gravitation, which "he afterwards applied to the planetary system, was "first calculated and ascertained by experiments "performed upon substances which were entirely at "his disposal.

"It will scarcely be denied either, that it is al"most exclusively to this department of experiment "that Lord Bacon has directed the attention of his "followers. His fundamental maxim is, that knowledge is power; and the great problem which he "constantly aims at resolving, is, in what manner "the nature of any substance or quality may, by ex

periment, be so detected and ascertained, as to "enable us to manage it at our pleasure. The great"er part of the Novum Organum, accordingly, is "taken up with rules and examples for contriving "and conducting experiments; and the chief ad"vantage which he seems to have expected from "the progress of these inquiries, appears to be cen"tered in the enlargement of man's dominion over "the material universe which he inhabits. To the "mere observer, therefore, his laws of philosophiz

ing, except where they are prohibitory laws, have "but little application; and to such an inquirer, the "rewards of his philosophy scarcely appear to have "been promised. It is evident, indeed, that no di"rect utility can result from the most accurate ob"servations of occurrences which we cannot con❝trol; and that, for the uses to which such obser

་

"vations may afterwards be turned, we are indebted, "not so much to the observer, as to the person who "discovered the application. It also appears to be pretty evident, that, in the art of observation it"self, no very great or fundamental improvement "can be expected. Vigilance and attention are all "that can ever be required in any observer; and though a talent for methodical arrangement may "facilitate to others the study of the facts that have "been collected, it does not appear how our know➡ ledge of these facts can be increased, by any new "method of describing them. Facts that we are un"able to modify or direct, in short, can only be the

66

objects of observation; and observation can only "inform us that they exist, and that their succes"sion appears to be governed by certain general

"laws.

In

"In the proper experimental philosophy, every "acquisition of knowledge is an increase of power; "because the knowledge is necessarily derived from "some intentional disposition of materials, which we may always command in the same manner. "the philosophy of observation, it is merely a gra "tification of our curiosity. By experiment, too, "we generally acquire a pretty correct knowledge "of the causes of the phenomena we produce, as we "ourselves distribute and arrange the circumstances 66 upon which they depend; while, in matters of "mere observation, the assignment of causes must always be, in a good degree, conjectural, inasmuch "as we have no means of separating the preceding phenomena, or deciding otherwise than by analo

'gy, to which of them the succeeding event is to be "attributed."

As the whole of this passage tends to depreciate the importance of a very large department of Physics, no less than of the science of Mind, the discussion to which it leads becomes interesting to Philosophers of every description; and, therefore, it is unnecessary for me to make any apology, either for the length of the quotation, or for that of the examination which I propose to bestow on it. It is sufficient for me to remind my readers, that, in the remarks which follow, I plead the cause not only of Locke and his followers, but of such star-gazers as Tycho Brahe, Kepler, Galileo, and Copernicus.

That it is by means of experiments, judiciously conducted, that the greater part of the discoveries in modern physics have been made, I readily admit. Nay, I am satisfied, that it is by a skilful use of this great organ of investigation, much more than by any improvements in the art of observing the spontaneous appearances of the universe, that the physical inquiries of Bacon's followers are chiefly characterized, when contrasted with those of the ancient schools. The astronomical cycles handed down to us from the most remote antiquity; the immense treasure of facts with respect to natural history, preserved in the works of Aristotle and of Pliny; and the singularly accurate histories of the phenomena of disease, which some of the Greek physicians are allowed to have bequeathed to posterity, abundantly justify the remark which was long ago made by a medical writer, that, "if the ancients were not ac

"customed to interrogate Nature, they, at least, lis"tened to her with an unremitted attention." *

In farther illustration of the utility of experiment, it may be remarked, that, in proportion as a particular science opens a field to address and invention, in thus extorting the secrets of Nature, the rate of its progress is subjected to human genius and industry. What is the great cause of the uncertainty in which medicine continues to be involved? Is it not, that, in addition to the difficulties which it has to struggle with, in common with the other branches of physical knowledge, it depends, more than any of the rest, upon accident for its improvement? The experimentum periculosum, and judicium difficile, are complaints as old as the time of Hippocrates.

While, however, I make this concession in favour of experiment, as the most powerful organ we can employ in the study of Nature; and admit, in their fullest extent, the advantages peculiar to those sciences in which we can, at pleasure, avail ourselves of its aid; I must be allowed to add, that I am unable to perceive the slightest connection between the premises and the conclusion which they have been employed to establish. The difference between experiment and observation consists merely in the comparative rapidity with which they accomplish their discoveries; or rather in the comparative command we possess over them, as instruments for the investigation of truth. The discoveries of both, when actually effected, are so precisely of the same kind,

* Van Doeveren.

C