The diagrams, symbols, definitions, comparisons, and general language of science, now briefly alluded to, are familiar examples of the creations requisite for the philosophical explanation of the world. But anything these could suggest to an ordinary reader would give but a very faint notion of the vast range of intellectual machinery now in existence for handling the different classes of nature's sequences and connections. These definitions and general terms are wrought up into propositions, principles, or theorems, which give the mind an astonishing facility in transferring knowledge from one thing to another, which is the cardinal operation in all scientific proceedings. The theorems and devices of mathematics, the nomenclature of chemistry, the classifications of natural history, the descriptive language of anatomy, extend to a compass almost beyond the grasp of any single mind; and all is conducted on the principle of rigorously excluding extraneous emotions and feelings, and confining the mind to the view of properties and forms that are pertinent to the objects of the scientific man.

We have thus touched, so far as our limits will permit, on the intellectual workings or mental processes suitable for philosophical inquiry. The action of the mind always consists of a stream of successive impulses, images, conceptions, postures, or whatever name we may give to each single act of attention or mental engrossment; and this succession of impulses, conceptions, or pictures, is governed by a few simple laws expressive of the forces that drive us on from one notion to another. Now these forces that cause us to pass from thought to thought are the same for all mental streams whatever, but the thoughts and notions themselves may be very various. The march of the scientific mind is from proposition to proposition, from individual objects to scientific generalities, and from one stage of generality to another; the propositions and generalities being all rigorously confined to the properties and powers concerned in nature's causations. An iron discipline has enabled the scientific man to disregard the multifarious allurements of sensible objects, and to confine his regards to the isolated and meagre features that govern their actions upon one another, and to entertain only one species of actions at a time. Possessing his mind with these bare and selected features, and with the diagrams, symbols, definitions, theorems, and other representative creations suited to his purpose, he leaps from one to another through a long line of uninviting conceptions, and has usually for the conclusion of his march some piece of knowledge, some doctrine, or application of a doctrine, which embraces a link of causation or a coincidence of natural appearances. It would lead us too far if we were to present examples of these trains of mental successions, to which the designation of chains of abstract reasoning is sometimes applied; we must be content with merely hinting at their general character, and we trust to cast additional light upon them by the observations that we have still to make on the nature of legitimate science.

Having now detailed the various meanings attached to the term philosophy, together with the sentient and creative processes of the mind in its scientific workings, we shall endeavour to concentrate more specifically the essence of philosophy under a few distinct heads. All the various meanings given above merge more or less completely in three great divisions or

kinds, to which we may give the names of Theoretical Philosophy, Practical Philosophy, and Philosophies of Life. We shall briefly touch on each of these in succession.

THEORETICAL OR SPECULATIVE PHILOSOPHY.

The general or abstract sciences, which make up the body of Theoretical Philosophy, are the systematic expositions of the different departments of natural phenomena. There being, as already stated, in the causation of the world many distinct trains or threads, the necessities of man's limited intelligence require that each should be studied and recorded apart from the rest; hence we have a science of mathematics for the properties of number, quantity, and form, which do not in themselves involve causation, but are essential conditions in the statement of every kind of cause and effect. The sciences of causation are mechanics, astronomy, atomic cohesions, heat, light, electricity, chemistry, physiology, mind, and society. These represent the whole range of natural powers known to us, and they arrange the facts and laws respecting those powers in a manner best suited to their comprehension by the human intelligence.

Besides these pure and abstract sciences, each handling some one distinct department of nature's operations, and touching on other departments only in so far as they are inevitably involved in its own, there are a certain number of mixed sciences, which bring in no new ultimate principles or laws, but treat of phenomena locally associated in nature. Thus mineralogy is a mixed science, its causations are found among the mechanical, physical, or chemical laws; but it is convenient to treat as a separate branch of knowledge the concurrence of these various powers in one of nature's arrangements. We must not be for ever analysing and isolating the properties of natural bodies; we must be prepared to state what will be the collective action of a group of causes when they meet in the same subject, as in a mineral, metal, plant, or living creature. Hence sciences are formed with the view of treating natural objects as wholes, and taking account of every one of the peculiarities and forces of such objects. This is the origin of our natural history sciences-comprising mineralogy, botany, zoology, and geology as the leading members of the group. These are concrete sciences, as compared with physics, chemistry, and physiology, which belong to the general or abstract group: both sets are true sciences; but the one set adapt themselves to the aggregates or wholes presented in nature, the other search out and state apart the separate classes of properties or threads of causation.

In the building up of theoretical science by means of the appropriate inquiries, observations, experiments, inductions, deductions, hypotheses, classifications, &c. the legitimate motives and ends are such as the following:-The desire to attain an exact acquaintance with the order of natural events and of the associated appearances of the world of matter and mind, and for this purpose to penetrate the complicated mass of operations, and seize the single, ultimate, and indivisible threads of succession and links of companionship; the desire to reconcile all contradictions, and attain perfect consistency of views in every department of nature; the wish to possess

ourselves of the simple laws of creation, and trace their workings throughout; the longing after truth and certainty in our anticipations or predictions of the future as well as in retracing the past. The love of truth, consistency, and simplicity is the proper emotion of pure philosophy. Besides the gratification that may arise from the active exercise of intellect in its peculiar sphere, we may lawfully derive all the enjoyment that accrues from the tracing of similarity in apparent diversity, of unity in variety, of simplicity in complexity, of order in confusion. The clearing up of mysteries, and the successful comprehension of what seemed utterly beyond the ken of our faculties, may likewise delight the human spirit even to ecstasy. But these, though the legitimate, are not the only motives that have prompted men to apply themselves to the study of the world or to speculative philosophy.

The objects aimed at in the investigation of nature, the feelings associated with the pursuit, and the methods employed, have all undergone changes and modifications since the origin of speculative philosophy in the land of intellect in ancient Greece-in the sixth century before Christ. The misleading influences arising from the manifold aspect of nature and from the tendencies of the primitive mind gave a false turn to the whole inquiry at the very outset, and it took ages to arrive at the proper point of view. The first philosophers could never have suspected the abstruse and hidden character of the powers that keep up the processes of nature; they were also completely ignorant of what was the proper subject to commence with. Inheriting the prepossessions given by the early poets, they sought to find out some one great ruling power that gave birth to all the appearances of creation, as the originating and sustaining impulse. One set of inquirers selected a physical agency for this purpose, such as water or liquidity; another class fell upon metaphysical abstractions, and in so doing opened up the arena of metaphysical discussion to the human intellect.

Of all the toils, conflicts, battles, and perilous adventures that have given undying interest to the history and poetry of the past, there are none that would more thoroughly arouse the sympathies of an intelligent mind than the struggles of infant man to comprehend the scheme of the world or to assign the moving forces that guided it and the law of their operation. Setting aside the mystery of life and the nature of mind-which, however, by an unfortunate weakness of our nature, are the most attractive and fascinating subjects of inquiry-what origin could an early speculator assign to the winds and clouds, and hail and lightning? If he were content to assume the daily revolution of the starry sphere as a primitive impulse of the circular kind, he would still be puzzled with the irregularities of the planets, the changes of the moon, and the alterations in the length of the day. Then what could he make of fire terrestrial or celestial? The tides of the sea must be an astonishing enigma. Vegetation and animal life superadded to all other peculiarities would serve to complete the mighty maze. And if, standing in still amazement over this whole spectacle, he thought of his own existence in the midst of it, as a being plunged into a pathless wilderness obliged to move on, but with scarcely the faintest perception where or how, we shall with difficulty picture to ourselves his strange emotions and fancies. In time men get habituated to anything; to die is always before them as an issue in time

of difficulty; but the young fresh intellect of a gifted nature would have to pass through the melancholy pangs of perplexity, varied with wild gleams of hope and exultation bursting forth now and then as there rose to view an apparent solution of some one of the many mysteries of being. Solutions springing out of the depths of despair or the pride of intelligence were the philosophies of the ancient world.

Two eminent men stand out as taking a lead in their respective epochs in reforming the prevailing methods of inquiry - Socrates and Lord Bacon. But in modern ages the reformation has been principally owing to examples set by the individual inquirers whose better instincts and more correct intelligence were their guide; among these Galileo and Newton have a conspicuous place. In the midst of the varied studies of every age since philosophy began, there have always been a select few at work at the right end of the chain; and their labours gradually built up a mass of sure and permanent results, although for a long time these results fell short of the impatient curiosity of men. In the early centuries, when impossible problems were agitating the minds of the leading men, there grew up that precious contribution to mathematical knowledge contained in the works of Euclid and other Alexandrian geometers. In the wildest days of alchemy there were a few scattered chemists whose inquiries were sober and practical, and led to the greater part of the real knowledge of chemical substances that was accumulated in the middle age. Among the endless diversity of human characters, there occur at intervals men naturally free of the vices of their age, who can with little effort set an example of a better state of things; and in the scientific walk such cases have not been unfrequent. A powerful one-sided nature, utterly unsusceptible to the ordinary enticements and allurements of the world, and having for its peculiarity the love of those bare and naked forms, figures and properties, which causation hinges on, may fulfil the great destination of turning a bewildered world into the paths of successful inquiry.

At the present time, when science has advanced so far as to establish beyond question the legitimate ends of pursuit and the means of attaining them, by well-guarded observations, experiments, generalisations, and proofs, the errors of the past are for the most part matters of history. Yet in saying that the proper ends of science as well as its proper means are now generally recognised, we must except from the statement the branches of knowledge whose subjects touch most closely and directly on human feelings and interests the sciences, namely, of man and society. To these subjects imperfection of method still cleaves; and the obstacles that anciently obstructed the physical sciences, arising from the prejudices, prepossessions, and sentiments of primitive man, still operate in their case. The most striking portion of Lord Bacon's work on the reformation of philosophy, the Novum Organon,' consisted in an exposition of the prevailing obstructions in the way of a sound method of inquiry. To these he gave the expressive name of idola,' or idols, and he divided them into various species according to their origin. One class he denominated idols of the tribe, because they were corrupting influences belonging to universal human nature; a second class were idols of the cavern, or special influences at work on individuals; the third class were idols of the market-place, having their origin in social intercourse: under this head he illustrated the

abuses of language. The last class were idols of theatre-meaning the love of theatrical display and imposing effects, which he considered to be the motive of adherence to some of the systems of philosophy that had once been popular.

The most comprehensive exposition of 'idola' could scarcely include all the ways that the human mind is perverted and corrupted in its search after truth. Almost every feeling, instinct, emotion, and passion of human nature may come in as an obstacle; at all events it would be easier to specify the exceptions than to give a full detail of all that come under the rule. We have already alluded to the legitimate gratifications accorded to the human mind by a true scientific method and by the pure doctrines of science; but these gratifications being mostly founded in intellect must be the favourite enjoyment of the few rather than of the many.

In attempting to specify a number of the 'idola' or influences that obstruct the march of sound philosophy, we shall confine ourselves to two descriptions of them; selecting either those that are of a permanent character, owing to the nature of the human constitution, or those that more particularly attach to the present time.

1. The want of vigour and force in the human intellect in general is the foremost cause of the slowness of scientific discovery. The average run of human beings are utterly destitute of the endowments requisite for the accurate comprehension of nature's intricacies, far less for original discovery. The superficial aspects of things, the glitter and colour of outward appearances, the favourite likings, the hereditary traditions, the imperfections of ordinary speech, are too much for a mind where intellect is not of more than common power. As a general rule man is not made for seizing the true point of view of the world, or for setting aside appearance and delusive hopes to grasp at the actual links of power and certainty which govern the course of natural operations. An individual here and there among the privileged races of the globe possesses this faculty; but if ever it be called into exercise for this end, it must sustain the opposition caused by the general tendencies of the multitude in addition to the natural difficulties of the case. The hold that such individuals have on the world is derived partly from the influence of an ascendant intellect, and partly from the necessity that comes to be felt every now and then for correct information as to the course of the world where all live and move and have their being.

2. Aversion to the abstract method, a method we have seen to be essen tial to science-in other words, to those naked and artificial conceptions that are involved in the links of causation. The notions, symbols, and machinery of mathematics, the doctrines of atomic attractions and repulsions, the theory of latent heat, the refractions and undulations of light, the laws of chemical atoms, the structure of cells, fibres, and tissues, the abstractions that have been employed to give an icy touch to the warm emotions of humanity-are all extremely repulsive to the natural mind. It is felt as a great hardship that these notions are essential to the understanding of the plans and operations of the great workshop of creation. The coercion of intellect requisite for acquiring all these notions, and carrying on chains of reasoning by their means, is usually a painful process of discipline; and men in general would much rather that they had to deal