only with objects as they appear to the senses and in all the fulness of their manifestation. To speak of nine loaves, nine men, nine pounds, is always easy, but to carry on processes with numbers in general is a distasteful operation, requiring the salutary compulsion of the schoolmaster. It is pleasant to handle a rose, or rest under a spreading oak, but to be unable to comprehend the growth and production of these objects without a system of diagrams and obscure reasonings about the development of cells and the movements of invisible globules, seems a freak of nature to set off the luxury of sense by the labour of the intellect. No lesson is more incessantly taught to men than that they should use their intellectual faculties, and yet they have often found it an easier task to make the most slavish submissions to spiritual and temporal despotisms.

The progress of discovery, which in many cases, although not in all, leads to simplicity and intelligibility of doctrines, and to the advancement of the arts of exposition and style, tend more and more to take off the harsh edge of scientific forms, and to adapt them to the popular liking for the concrete in nature, and for displays to the senses. This is one of the most important aspects of our civilisation, seeing that the accurate comprehension of the world, instead of being the prerogative of a few, is indispensable to the happiness and wellbeing of all.

It is the business of poetry and art to work up the concretes or totals of nature, or to confer direct enjoyment and a cultivation apart from the discipline and truth - giving possessions of science. In some rare instances the interest of scientific expositions approaches to the poetic: the large objects and sublime periods of astronomy and geology; the beautiful symmetries disclosed in mineral as well as in vegetable and animal structures; the mysterious grandeur of the subtile powers of heat, electricity, and light; the structure of human thought and emotion—may stimulate the curiosity and excite the attention of men, like a work of high art, but such cases must not mislead us into supposing that there is any close affinity between art and science. Contrariety and contrast are the essential relation between the two. The 'poetry of science' is not a proper combination of terms: the incongruity of the designation is apparent at once if we take an extreme case of each, and compare the Psalms of David with a treatise on algebra, or Hamlet with Quain's Anatomy.

3. A grand obstacle to the attainment of scientific truth has arisen from the reluctance and the inability to understand what knowledge is, or what the human mind can really attain to in the comprehension of the world. There has been all along a struggle both to go farther back into the origin of things and to penetrate deeper down into their essence and nature than becomes the faculties of our nature as at present constituted. We stand looking at a stream of events and successive appearances, and we are able to ascertain the things that go in company and the things that uniformly succeed each other; and by possessing the knowledge of these uniformities of coincidence and succession we can go a certain way forward in anticipating the future and a certain way backward in retracing the past; but we cannot by any inquiries of ours attain a knowledge of the first commencement of things, or see deeper into their essence than by conceiving them as they appear to our senses and reason with all their relations of companionship and sequence. Of gravity we can only know the fact of the

mutual approach of all material substances according to a certain invariable rate; and to seek for any other hold of the phenomenon is to labour in vain. 4. Considerable misapprehension arises from the disposition to dictate the purpose or end that the Creator had in view in the various objects around us. In this, as in other sources of error, we are apt to transfer our own personality to the large operations of the world; and because in our little sphere of action we view everything according to its utility in the affairs of life, we rise to the belief that a similar utility is the final end of all creation. This feeling makes us ready to receive implicitly any statements as to the facts of the world that shew design according to our notions of design; whereas all such inferences should at the very least be postponed till our knowledge of the facts has become clear and precise beyond all doubt. The consideration of final ends has in various remarkable instances thrown light upon the structure of animal organisations; but the greatest caution is requisite in using this as a means of discovery or explanation.

5. We may notice next the obstructions arising from preconceptions as to what is proper, perfect, or becoming in nature's arrangements. The belief in the circular nature of the planetary motions is the most notable example of this tendency-it having been assumed that a circle was perfection, and that no other figure suited the dignity of a planet.

It would be easy to enumerate a variety of objections that have one after the other been proved, beyond the possibility of cavil, to be erroneous, although previously assumed to be valid. We need, however, only refer to Harvey's discovery of the circulation of the blood, and Jenner's discovery of the properties of vaccination; both of which were at first assumed to be at variance with truth, yet were finally established as correct. In the latter of these questions there mingled-as there does in many other questions—a sentiment of repugnance at the idea of human beings having anything in common with the constitution of the brutes. Now the doctrine might or might not be true; but it is perfectly irrational to suppose that its bearing upon human pride could have been any presumption against it. Such facts, in connection with the progress of knowledge, should have the effect of inducing much caution in judging of new discoveries in physical science.*

In social doctrines the intrusion of preconceived notions is still more frequent and more mischievous. Regardless of the actual facts, we insist

Archbishop Whately distinguishes between two kinds of discoveries of truththe communication of the one of which he calls information, and of the other instruction. The former relates to matters of fact not known before, such as the distance of the earth from the sun. 'The communication of this kind of knowledge is most usually, and most strictly, called information. We gain it from observation, and from testimony. No mere internal workings of our own minds (except when the mind itself is the very object to be observed), or mere discussions in words, will make a fact known to us; though there is great room for sagacity in judging what testimony to admit, and in the forming of conjectures that may lead to profitable observation, and to experiments with a view to it. The other class of discoveries is of a very different nature. That which may be elicited by Reasoning, and consequently is implied in that which we already know, we assent to on that ground, and not from observation or testimony. To take a geometrical truth upon trust, or to attempt to ascertain it by observation, would betray a total ignorance of the nature of the science.'

on finding in nature what we consider suitable to human happiness. We are apt to assume that because man exists that therefore all things necessary for his wellbeing-according to our ideas of it-must also exist, and that nothing but bad laws or bad government stands in the way of the universal happiness of the race. When Malthus put forth a statement as to the necessity of limiting the increase of population in order to increase the dividend of wealth, instead of discussing his doctrine like any other interpretation of the facts of the world, a storm of indignation was raised at the very thought of such a thing, which has taken more than a generation to subside. Again, it is supposed that because we are born with certain desires we shall, as a matter of course, find the means of their gratification; whereas the facts of the world teach us that many of our desires can never be gratified, and that for our own quietness it is absolutely essential to restrain, and almost extinguish many appetites and longings, and content ourselves with the gratification of only a very small fraction of human wishes. Nature will often turn a deaf ear to our most earnest prayers and most amiable and refined longings.

6. The love of the marvellous is remarkable for its influence in corrupting our faculties in the search after natural truth. From the fascination and stimulus of this class of objects they are purposely brought together in romantic and other compositions intended for agreeable excitement. What is familiar, ordinary, common, being apt to lose its interest and become stale, we take delight in encountering what is extraordinary, startling, and opposite to our usual experience. The stars cease to arrest our gaze, but a meteor flashing across the sky draws every eye upon its course. The sun and moon become objects of intense interest when in the rare and striking situation of an eclipse. Events either strongly contrasting with the usual run of things, or rising far above ordinary in magnitude, grandeur, or imposing effect, are the seasoning of life's dulness. To see, and afterwards to relate, uncommon occurrences and objects at variance with all experience, is delightful to wise and ignorant alike; but to rude ages and uncultivated minds novelties, rarities, and marvels are especially agreeable.

Now this itch for marvels is very apt to interfere with the cool observation of facts, and still more with the record and narration of them to others. Of course in phenomena of a rare and striking kind the difficulty of avoiding exaggeration is increased. In such things as earthquakes, meteors, eclipses, and rare and extraordinary productions, none but a highly-disciplined mind is capable of giving unvarnished statements to others, or forming an accurate conception to itself.

There are two subjects where the love of the marvellous has especially retarded the progress of correct knowledge the manners of foreign countries, and the instincts of the brute creation. To exaggerate and make known signs and wonders is the standing vice of travellers, even when they do not absolutely manufacture fictions. The early travellers, going abroad with the notions of superstitious ages, and with little discipline in the arts of observation and correct writing, could in general be so little trusted that the cautious part of the public looked with suspicion upon marvellous statements in general, and in some instances discredited what was actually true. The greatest traveller of antiquity

and the earliest accurate historian* repeatedly and expressly refrains from mentioning what he saw from anticipating the incredulity of his readers, who, while delighting in certain kinds of the marvellous, might bring into play another instinct of uncultivated human nature—namely, the tendency to measure the whole world by the narrow standard of our own limited experience.

It is extremely difficult to obtain true observations of the instincts of animals from the disposition to make them subjects of marvel and astonishment. Many people take delight in storing up tales of the extraordinary sagacity of dogs, cats, horses, birds, &c. in doing things quite incomprehensible and inexplicable in any law of nature whatsoever. It is nearly as impossible to acquire a knowledge of animals from popular stories and anecdotes, as it would be to attain a knowledge of human nature from the narratives of parental fondness and friendly partiality.

7. The thirst for premature explanations of the world's obscurities, so natural to the class of minds whose intellectual tastes are strong, is a cause of evil as well as of good. It is hard to feel an utter incapacity to know what is within the reach of the human faculties, and will one day be blazed abroad in the clearest daylight. Rather than wait for the natural evolution of the doctrines and views that will suffice to explain the mysterious powers of life and organisation, the impatient mind seizes upon some plausible supposition, and intrudes it by main force into the appearances, thereby incurring the temptation to slur over difficulties and misrepresent facts for the sake of maintaining the credit of its misplaced ingenuity. A very great number of the hypotheses and opinions constituting the history of philosophy belong to the class of premature and impossible attempts. There is an order to be observed in the course of discovery: we must advance from the simple to the compound; and if we have set our heart upon knowing the laws of causation in any complex subject-such as the growth of living tissues-we must first ascertain the laws of the separate agencies that enter into the complex action. For example, the growth of a vegetable is brought about by a host of distinct powers or causes. can see in it the presence of the cohesive or aggregating agency which binds the atoms of bodies together into masses, the expanding and transforming energy of heat, the attraction of tubes for liquids, the solvency of watery fluids, chemical combinations and decompositions, the action of light—which is at present not distinctly understood the formation of cells from one another, and there may be many more agencies besides. Now until each one of these influences has been well studied in circumstances where it stands out apart from the others, it is utterly hopeless to attempt to render an account of the complex stream where all run together. A scientific man will never willingly enter on the investigation of any difficulty until he conceives that all the questions that go before it as preliminaries have once been settled. As science advances, it becomes more easy to see what subjects stand next in order for inquiry; but in early times there was the greatest confusion and mistakes on this point.

We

In the foregoing enumeration of obstacles to sound philosophy we have

* Herodotus.

only selected some of the more prominent, it being impossible for us to present a complete and exhaustive catalogue. We have passed over influences of a more special and individual kind—such as the various forms of human vanity and egotism, the sinister ends of interested sects, the pleasures of illusion and hope, and other susceptibilities which an orator is permitted to work upon to serve the passing ends of everyday life. The taste for what is true and certain has much to contend against, and at times its struggles rise to the tragic and sublime. The total submission of the entire being to what has been proved by evidence is the crowning-point of the scientific character; it is the ascendancy of truth and reason, the victory of pure intelligence over all the workings of sense and passion, a still small voice making itself heard amidst the war of elements.

PRACTICAL PHILOSOPHY.

Philosophy has from a very early period been associated more or less with the practical ends and business proceedings of life. The two great agitations for philosophic reform, the one in the ancient world and the other in the modern-the movements of Socrates and Bacon-set forth prominently the need of a more practical turn being given to men's inquiries into nature. When the doctrines and principles of science are so shaped and adapted as to supply guidance to some branch of human business or occupation, science or philosophy is then said to be practical, and the practice so guided is said to be scientific or philosophical. A modern treatise on navigation is a fair example of this union of theory and practice; the abstract doctrines of mathematics, astronomy, and physics are selected, brought together, and arranged so as to suit the practical emergencies of seamanship. Instead of teaching all that the faculties of man have been able to make out respecting geometry and astronomy, and presenting it in the order best fitted for the comprehension of the whole, a selection is made of certain propositions in each science, which help to solve the practical problems arising in navigation; and a number of rules are devised for shortening the work as much as possible. The delight in mathematical truth, and the taste for abstract speculation and comprehensive knowledge, are not recognised as inhering in the seafaring mind: should such tastes exist over and above the necessities of the navigating art, they are provided for by the works that discuss science in general, or by treatises in the various departments of theoretical philosophy. These departments we have already enumerated.

The adaptation of science to practice, and the reference by practice to science, have been insisted on by sound-thinking men as equally necessary for both. If science were conducted merely for the gratification of the intellectual tastes, or to enable a few people to live what is called a life of contemplation-which some of the Greek philosophers were wont to call the highest life-the danger would be that rigid certainty of doctrines would give way to luxurious and pleasing notions capable of contributing to this peculiar mode of enjoying existence. It is the application to practice that makes the test of theories. The doctrines of gravitation, and the theories of the sun, moon, and planets, are daily subjected to the ordeal