on what was generally understood to be the great object of inquiry; I mean, on the mode of communication between the mind and the material world : and, in truth, amounts only to a precise description of the fact, stripped of all hypothefis, and ftated in fuch a manner as to give us a diftinct view of the infurmountable limits which nature has in this inftance prescribed to our curiofity. The fame obfervation may be made, on the reaonings of this profound and original author, with refpect to fome metaphyfical queftions that had been ftarted on the fubject of vifion; in particular, concerning the cause of our feeing objects fingle with two eyes, and our feeing objects erect, by means of inverted images on the retina.

If we were to examine, in like manner, the prefent ftate of morals, of jurifprudence, of politics, and of philofophical criticifm; I believe, we fhould find, that the principal circumftance which retards their progrefs, is the vague and indiftinct idea, which those who apply to the ftudy of them have formed to themselves of the objects of their researches. Were these objects once clearly defined, and the proper plan of inquiry for attaining them illuftrated by a few unexceptionable models, writers of inferior genius would be enabled to employ their induftry to much more advantage; and would be prevented from adding to that rubbish, which, in confequence of the ill-directed ingenuity of our predeceffors, obftructs our progrefs in the purfuit of truth.

As a philofophical fyftem of logic would affift us in our particular fcientific inveftigations, by keeping fteadily in our view the attainable objects of human curiofity; fo, by exhibiting to us the relation in which they all ftand to each other, and the relation which they all bear to what ought to be their com mon aim, the advancement of human happiness, it would have a tendency to confine induftry and gen.

ius to inquiries which are of real practical utility; and would communicate a dignity to the moft fubordinate pursuits, which are in any respect fubfervient to fo important a purpose. When our views are limited to one particular fcience, to which we have been led to devote ourselves by taste or by accident, the course of our ftudies resembles the progrefs of a traveller through an unknown country; whofe wanderings, from place to place, are determined merely by the impulfe of occafional curiofity; and whofe opportunities of information must neceffarily be limited to the objects which accidentally prefent themselves to his notice. It is the philofophy of the mind alone, which, by furnishing us with a general map of the field of human knowledge, can enable us to proceed with fteadiness, and in an ufeful direction; and while it gratifies our curiofity, and animates our exertions, by exhibiting to us all the various bearings of our journey, can conduct us to those eminences from whence the eye may wander over the vaft and unexplored regions of science. Lord Bacon was the first person who took this comprehensive view of the different departments of ftudy; and who pointed out, to all the claffes of literary men, the great end to which their labors fhould confpire; the multiplication of the fources of human enjoyment, and the extenfion of man's dominion over nature. Had this object been kept fteadily in view by his followers, their discoveries, numerous and important as they have been, would have advanced with ftill greater rapidity, and would have had a much more extenfive influence on the practical arts of life.*

* Omnium autem gravissimus error in deviatione ab ultimo doctrinarum fine consistit. Appetunt enim homines scientiam, alii ex insita curiositate et irrequieta; alii animi causa et delectationis, alii existimationis gratia: alii contentionis ergo, atque ut in disserendo superiores sint: plerique propter lucrum et victum; paucissi

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From such a system of logic, too, important affiftance might be expected, for reforming the established plan of public or academical education. It is melancholy to reflect on the manner in which this is carried on, in moft, perhaps, I might fay, in all the countries of Europe; and that in an age of comparative light and liberality, the intellectual and moral characters of youth should continue to be formed on a plan devised by men, who were not only ftrangers to the business of the world, but who felt themselves interested in oppofing the progress of useful knowledge.

For accomplishing a reformation in the plan of academical study, on rational and fyftematical principles, it is neceffary, in the first place, to confider the relation in which the different branches of literature, and the different arts and sciences, ftand to each other, and to the practical purposes of life: and fecondly to confider them in relation to the human mind, in order to determine the arrangement, beft fitted for unfolding and maturing its faculties. Many valuable hints towards fuch a work may be collected from Lord Bacon's writings.

II. Another very important branch of a rational fyftem of logic (as I had occafion already to obferve) ought to be; to lay down the rules of inveftigation which it is proper to follow in the different sciences. In all of thefe, the faculties of the understanding are the inftruments with which we operate; and without a previous knowledge of their nature, it is impoffible to employ them to the beft advantage. In every exercise of our reasoning and of our inventive powers, there are general laws which regulate the progrefs of the mind; and when once thefe laws

mi, ut donum rationis, divinitus datum, in usus humani generis impendant.Hoc enim illud est, quod revera doctrinam atque artes condecoraret, et attolleret, si contemplatio, et actio, arctiore quam adhuc vinculo copularentur. De Aug. Scient. lib. i.

are afcertained, they enable us to fpeculate and to invent, for the future, with more fyftem, and with a greater certainty of fuccefs.-In the mechanical arts, it is well known, how much time and ingenuity are mifapplied, by those who acquire their practical skill, by their own trials, undirected by the precepts or example of others. What we call the rules of an art, are merely a collection of general obfervations, fuggefted by long experience, with refpect to the most compendious and effectual means of performing every different ftep of the proceffes which the art involves. In confequence of fuch rules, the artift is enabled to command the fame fuccefs in all his operations, for which the unskilled workman must truft to a happy combination of accidental circumftances; the mifapplications, too, of the labor of one race are saved to the next; and the acquifition of practical address is facilitated, by confining its exertion to one direction. The analogy is perfect, in those proceffes which are purely intellectual; and to regulate which, is the great object of logic. In the cafe of individuals, who have no other guide to direct them in their inquiries than their own natural fagacity, much time and ingenuity muft inevitably be thrown away, in every exertion of the inventive powers. In proportion, however, to the degree of their experience and obfervation, the number of thefe mifapplications will diminish; and the power of invention will be enabled to proceed with more certainty and steadiness to its object. The misfortune is, that as the aids which the understanding derives from experience, are feldom recorded in writing, or even defcribed in words, every fucceeding inquirer finds himself, at the commencement of his philofophical purfuits, obliged to ftruggle with the fame difadvantages which had retarded the progress of his predeceffors. If the more important practical rules, which habits of investigation fuggeft to in

dividuals, were diligently preferved, each generation would be placed in circumftances more favorable to invention than the preceding; and the progrefs of knowledge, inftead of cramping original genius, would affift and direct its exertions. In the infancy of literature, indeed, its range may be more unbounded, and its accidental excurfions may excite more aftonishment, than in a cultivated and enlight. ened age; but it is only in fuch an age, that inventive genius can be trained by rules founded on the experience of our predeceffors, in fuch a manner as to infure the gradual and regular improvement of fcience. So juft is the remark of Lord Bacon: "Certo fciant homines, artes inveniendi folidas et "veras adolefcere et incrementa fumere cum ipfis "inventis."

The analogy between the mechanical arts, and the operations of scientific invention, might perhaps be carried further. In the former, we know how much the natural powers of man have been affifted, by the use of tools and inftruments. Is it not poffible to devise, in like manner, certain aids to our intellectual faculties?

That fuch a query is not altogether chimerical, appears from the wonderful effects of algebra (which is precifely fuch an inftrument of thought, as I have been now alluding to) in facilitating the inquiries of modern mathematicians. Whether it might not be poffible to realife a project which Leibnitz has fomewhere mentioned, of introducing a fimilar contrivance into other branches of knowledge, I fhall not take upon me to determine; but that this idea has at leaft fome plaufibility, muft, I think, be evident to those who have reflected on the nature of the general terms which abound more or lefs in every cultivated language; and which may be confidered as one fpecies of inftrumental aid, which art has discovered to our intellectual powers. From the observations which I