are more closely packed, and follow no such definite arrangement. The ovaries are simple sacs in both Bipalium and Rhynchodemus, and are placed very far forwards in the head, a long distance from the uterus. In Bipalium, short branches given off from the posterior positions of the oviduct are the rudi. ments of a ramified ovary, such as exists in Dendrocælum lacteum. The organs described as nervous ganglia by Blanchard in Polycladus are almost certainly its testes and ovaries, and therefore the arrangement of these bodies in Polycladus is the same as that in Bipalium. The nervous system is ill defined, but appears to consist of a network of fibres without ganglion cells, which lies within the primitive vascular canals. Numerous eye-spots are presented in Bipalium, most of them being grouped in certain regions in the head, but some few being found all over the upper surface of the body, even down to the tail. In Rhynchodemus two eyes only are present. All gradations would appear to exist between the simple unicellular eyespot of Bipalium and the more complex eye of Leptoplana or Geodesmus, where the lens is split up into a series of rod-like bodies, forming apparently a stage towards the compound eyes of Articulata. In considering the general anatomy of Bipalium, it is impossible to help being struck by the many points of resemblance between this animal and a leech. Mr. Herbert Spencer has, in .his "Principles of Biology," placed a gulf between Planarians and leeches by denoting the former as secondary, the latter as tertiary aggregates, so called because consisting of a series of secondary aggregates formed one behind the other by a process of budding. It is obvious, however, that a single leech is directly comparable to a single Bipalium. The successive pairs of testes, the position of the intromittent generative organs, the septa of the digestive tract, and most of all, the pair of posterior cæca, are evidently homologous in the two animals. Further, were leeches really tertiary aggregates, the fact would surely come out in their development, or at least some indication of the mode of their genesis would survive in the development of some annelid. Such, however, is not the case. The young worm or leech is at first unsegmented, like a Planarian, and the traces of segmentation appear subsequently in it, just as do the protovertebræ in vertebrates which Mr. Spencer calls secondary aggregates. If Mr. Spencer's hypothesis was correct, we should expect to find at least some Annelid developing its segments in the egg as a series of buds. It is not, of course, here meant to be concluded that Annelids are not sometimes in a condition of tertiary aggregation, as Nais certainly is when in a budding condition, but that ordinarily they are secondary and not tertiary aggregates, and if so, then so also are Arthropoda. "On a new Locality of Amblygonite, and on Montebrasite, a new hydrated Aluminium and Lithium Phosphate." By M. Des Cloizeaux. Geological Society, Feb. 5, Warington W. Smyth, F.R.S., vice-president, in the chair. The following communication was read:"On the Oolites of Northamptonshire.-Part II." By Samuel Sharp, F.G. S. In the first part of this memoir the succession of beds in the neighbourhood of Northampton was shown to be as follows: The Great Oolite limestone of this section has been confounded, even up to the present time, with a limestone (frequently Oolitic) which occurs between Kettering and Stamford, is prevalent about the latter town, extends through Rutland and Lincolnshire (where it attains a thickness exceeding 200 feet) and into Yorkshire, which limestone has been distinguished by Mr. Judd as the "Lincolnshire limestone." The object of the author was to show that these two limestones were distinct, and that while the former was of the Great Oolite period, the latter as certainly belonged to the Inferior Oolite; and in citing evidence in proof of this position upon stratigraphical and paleontological grounds, he gave a general account of the geology of the northern The same sequence, with the occasional superaddition of the Great Oolite Clay, was shown to be repeated upon the western escarpment of the Ise, at Glendon, Barford Bridge, near Rockingham at Weekly, and at Geddington (the Lincolnshire limestone increasing in thickness at every advance), and to occur over and over again upon innumerable escarpments in the counties of Northampton, Rutland, Lincoln, and York, offering unmistakeable and incontrovertible evidence of the true strati graphical position of the Lincolnshire limestone. February 21.-Annual General Meeting. His Grace the Duke of Argyll, K.T., F.R.S., president, in the chair. The Secretary read the Reports of the Council, ani of the Library and Museum Committee. The general position of the Society was described as satisfactory, and the number of Fellows is said to have essentially increased. In presenting the Wollaston Gold Medal to Sir Philip de Malpas Grey-Egerton, Bart, F.R.S., F.G.S., the president spoke as follows:-"Sir Philip Egerton,-I consider myself fortunate in being the organ of the Geological Society in presenting you with the Wollaston Medal, which has been awarded to you by the Council for the present year. The eminent ser vices which you have rendered to geology during a period now extending over forty years have long been familiar to scientific men, and have given you more than a European reputation. These services have been so great and so universally recognised, that the only difficulty I now have is not in assigning grounds for the vote which I have the pleasure of announcing, but in ex. plaining why it has been so long delayed. That delay has been occasioned, I believe, solely by the fact that you have yourself been so long an honoured member of the Council whose duty it is to consider the claims of geologists for the honours of this Society; and whatever influence you have had in that body has doubtless been exerted in favour of others to the exclusion of yourself. It is at least some compensation for the loss which the Council sustains in your absence that it is now able to accord a recognition which has long been due. The many papers which you have contributed to this Society from 1833 down to the present time are a sufficient indication of the wide range of your observations. But the special attention you have bestowed, and the light you have thrown on the structure and affinities of fossil fishes and reptiles, have been of the highest value, and have formed in the aggregate a most important contribution to our knowledge of the history of organic life. I have the highest pleasure in now handing to you the Wollaston Medal." Sir Philip Egerton, in reply, said :-"My Lord President, I know not whether it is owing to the poverty of the English language or to my unskilfulness in use of it, but I am quite at a loss for words adequate to express my appreciation of the great and unexpected honour conferred upon me by the award of the Wollaston Medal, and for appropriate terms to convey to your Grace my acknowledgments of the kind, but too flattering terms you have used in communicating the decision of the Council; and my embarrassment is increased by the con sciousness that, in comparison with those illustrious names which already adorn the Wollaston roll, I am quite unworthy of this great distinction. I cannot presume to think that the humble contributions I have been enabled to make to geological knowledge (and indeed to but a limited branch of it) can have been weighed in the balance against the labours of many others on both sides of the Atlantic, whose lives have been devoted to geological research, but who have not yet attained the distinction awarded to me to-day. In comparison with these my claims are quite insignificant. I must therefore look elsewhere to discern the motive which has influenced the Council in selecting my name on the present occasion in preference to others whose scientific claims are far greater than my own, and I think I am right in assigning it to a desire on their part to recognise, encourage, and occasionally reward the labours of those who although their lot in life has been cast in a sphere entailing many paramount duties which ought not to be neglected, nevertheless devote their leisure time to the promotion of scientific research rather than waste it in frivolous and unproductive amusements. In this sense I interpret the mind of the Council in awarding me this medal, and in this sense, as also as a stimulus and incentive to persevere in the cause of that science in which I take so deep an interest, and from the study of which I have derived so much intellectual enjoyment, I can, without arrogance, most gratefully accept it. May I be permitted to add, that if anything could enhance the feelings of gratification I experience in receiving this, the blue ribbon of geology, it is that it is presented by a President who, although occupying the highest social rank, and called by our gracious Sovereign to fill the highest offices of State, entailing most onerous duties and grave responsibilities, has nevertheless devoted himself to the study of scientific problems, and has inscribed for himself a name on the tablets of scientific literature, indelible so long as the Reign of Law shall continue to exist." The President then presented the balance of the proceeds of the Wollaston Donation-Fund to Mr. J. W. Judd, F.G.S., and addressed him as follows:-"Mr. Judd,-I have much pleasure in delivering to you the award of the Council of this Society in recognition of your valuable researches in the Neocomian and Jurassic rocks of England, researches which you are now extending with such marked success to the Secondary and Paleozoic rocks of Scotland. I rejoice to know that you are to carry to an investigation of the West coast of Scotland the experience and knowledge you have shown in your recent account of the Secondary rocks of the East coast. The scattered and broken remains of the Oolites in the Hebrides constitute a most interesting field of investigation; and a detailed examination of them conducted by you cannot fail to cast important light on many geological problems of the highest interest to our science. Mr. Judd made the following reply:-"My Lord President,The recollection of an occasion like the present may well be cherished by a student of science as an incentive to exertion Second only to the enthusiasm of research itself. Having learned to look to this Society, and never in vain, for the encouragement of sympathy and the guidance of criticism, it is with especial gratification that I receive this mark of confidence at the hands of my teachers and fellow-workers. When I think of the origin and traditions of this bequest-the objects contemplated by its illustrious founder, the distinguished geologists who have been its former recipients, and the important researches to which it has been made contributory-I am deeply impressed by the trust which you have reposed in me. It is my hope that by earnest labour I may be able to testify that my feelings of gratitude are not evanescent, nor my sense of responsibility light, in connection with the great honour which you have this day done me." I The I resident then presented the Murchison Medal to Mr. William Davies, of the British Museum, and addressed him as follows:-"Mr. Davies, I have much pleasure in delivering to you the Murchison Medal, which has been awarded to you by the Council of this Society in recognition of the services you have rendered to Paleontology, in the skill and knowledge you have displayed in the reconstruction of extinct forms of life. have the more pleasure in giving this medal, as I believe you will have the greater pleasure in receiving it, from the fact that it is the first award made under and in fulfilment of the will of the great geologist and excellent man whose loss we have all had so lately to deplore. I trust it may long serve to stimulate others to such services as you have rendered, and which have appeared to the Council of this Society to make you a worthy recipient of the First Murchison Medal." Mr. Davies in reply said :-"My Lord Duke, I desire to return my most sincere thanks to your Grace as President, and to the Council of this Society, for the honour they have conferred upon me in awarding me the Murchison medal. It is extremely gratifying to find that the humble services I have rendered to Paleontological science have been so kindly appreciated and deemed worthy of this high recognition. The pleasure is greatly enhanced by the fact that I have never considered my scientific work of sufficient importance to deserve any recog nition-the acquisition of scientific knowledge and the happiness of communicating it to others having, in my own case, been its own reward. I shall now feel it to be my duty as well as my ambition to render myself more worthy of the distinction you have this day conferred upon me-one which has also an especial significance to a servant of that great National Institution for which Sir Roderick Murchison so long and beneficially acted as a Trustee." The President then delivered to Prof. Ansted, F.R.S., For. Sec., for transmission to Prof. Oswald Heer, of Zürich, the balance of the Murchison Fund, and spoke as follows:-"Mr. Secretary, The labours of Prof. Heer in fossil botany and entemology have this year been recognised by this Council in the vote of the Murchison Fund. No branch of Paleontology requires more minute research, more careful comparison, more circumspect conclusions-and there are none, I may add, which, when so conducted, are richer in suggestions on the history of geological change. The fragmentary character which generally belongs to terrestrial and especially to botanical remains, places the study of them under special difficulties, difficulties which have been met with special skill by Prof. Heer. The remains of the Miocene flora are connected with some of the most perplexing problems of our science, and the light which has been thrown upon them by Prof. Heer more than deserves the recognition which I have now the pleasure of delivering into your hands for transmission to that distinguished man. This is the second mark of recognition which this Society has given to Prof. Heer, the Wollaston Donation Fund having been voted to him in 1862." Prof. Ansted having suggested that Sir Charles Lyell, as a particular friend of Prof. Heer's, might very appropriately speak in his name, Sir Charles Lyell in reply referred briefly to the nature of Prof. Heer's work, and said that he was sure that gentleman would appreciate highly this renewed expression of the interest taken by the Geological Society in his pursuits. Sir Charles Lyell remarked further, that he was particularly gratified that this award had been made at the present time, as Prof. Heer was well advanced in years and in an exceedingly infirm state of health, so that perhaps, another opportunity of showing him respect and sympathy might not occur. The President then read his Anniversary Address, in which he discussed the phenomena of denudation, referring especially to the influence of subterranean and other movements of the crust of the earth upon the denudation of its surface, and disputing the greatness of the denuding effects of glacial action. The Address was prefaced by biographical notices of deceased Fellows, including Prof. Sedgwick, Dr. Kelaart, Mr. Augustus Smith, Mr. N. Beardmore, and Prof. Pictet.-The Ballot for the Council and Officers was taken, and the following were duly elected for the ensuing year :-President: the Duke of Argylĺ, K.T., F.R.S.; Vice-Presidents: Prof. P. Martin Duncan, F.R.S.; R. A. C. Godwin-Austen, F. R.S.; Joseph Prestwich, F.R.S.; Prof. A. C. Ramsay, LL.D., F.R.S. Secretaries : John Evans, F.R.S.; David Forbes, F. R.S. Foreign Secretary Warington W. Smyth, F.K.S. Treasurer: J. Gwyn Jeffreys, F.R.S. Council Prof. D. T. Ansted, F. R.S.; the Duke of Argyll; W. Carruthers, F.R.S.; Prof. P. M. Duncan, F.R.S.; Sir. P. de M. G. Egerton, Bart., M.P., F.R.S.; R. Etheridge, F. R.S.; J. Evans, F.R.S.; J. Wickham Flower; D. Forbes, F.R.S.; Capt. Douglas Galton C. B., F. R.S.; R. A. C. Godwin-Austen, F. R. S.; J. Whitaker Hulke, F.R.S.; J. Gwyn Jeffreys, F.R.S.; Sir Charles Lyell, Bart., F.R.S.; C. J. A. Meyer; J. Carrick Moore, F.R.S.; J. Prestwich, F.R.S.; Prof. A. C. Ramsay, F.R.S.; R. H. Scott, F.R.S.; W. W. Smyth, F.R.S.; Prof. J. Tennant, F.C.S.; W. Whitaker; Rev. T. Wiltshire, M.A., F.L.S. Meteorological Society, Feb. 19.-Dr. J.W.Tripe, president, in the chair. The following papers were read:-"A description of an electrical self-registering Anemometer and rain-gauge," by the Rev. F. W. Stow, M. A. The general principle on which the registering apparatus is constructed is that of the Morse telegraph instrument as worked in America. The tape is drawn by a clock at the uniform rate of 6 inches per hour. As it passes over a grooved brass roller, holes are punched in it by a sharp steel point, drawn down by an electromagnet whenever the electric circuit is completed, and drawn back by a spiral spring when the contact is broken. There are two grooves in the roller and two electro-magnets, one of which is worked by the anemometer, and the other by the rain-gauge. Thus, when both magnets are in operation, two parallel rows of holes are punched in the tape. - On the Madras Cyclone of May 2, 1871," by Captain H. Toynbee, F. R.A.S. After giving extracts from several logs containing data taken during the time of the hurricane, and observations taken at the Madras Observa tory; the author says it seems fair to conclude that the centre of this cyclone passed to the W. and probably to the N. W. between the parallels of 10° and 13° N.; that its route was probably much interfered with by the high land to the W. and S.W. of Madras; but that it caused very disturbed weather on the west coast of India. The paper concludes with some practical suggestions as to how ships might more safely ride out a gale."On the character of the storm of August 21 and 23, 1868, over the British Isles," by Captain T. O. Watson. PARIS Academy of Sciences, Feb. 17.-M. de Quatrefages, president, in the chair. A decree of the President of the Republic authorising the election of M. Janssen to the Academy was read, and M. Janssen admitted. M. Faye read the termination of his answer to Fathers Secchi and Tacchini; it was devoted to the refutation of Secchi's statement that spots were solar eruptions and the proof that they were down-rushes caused by cyclones.-M. A. Trecul read a paper on the carpellary theory as regards Martynia fragrans.-M. A. de Caligny contributed a further paper on hydraulic engineering, &c.-Colonel H. Levret sent a note on the determination of geographical position on any elipsoid, and M. Boutin a note on the presence of nitre in Amarantus Blitum; the dried plant contains 11 68 parts per cent. by weight of potassic nitrate.-M. T. Tissandier presented a description of some meteorological observations made in a balloon.-M. L. Hugo sent a note on two antique dodecahedra in the Louvre, and M. Brachet two microscope lenses made of spinelle ruby; he believes that these will act better than the portion of the object-glass which is usually made of crown glass. A letter from P. Tacchini with a drawing of the remarkable appearance of Jupiter during January was received.-M. J. Bourget sent a paper on the mathematical theory of Pinaud's experiinents on the sounds produced by heated tubes.-M. Wurtz presented a note from Dr. L. C. de Coppet on the recent communications of MM. Gernez and Vander Mensbrugghe on super-saturated solutions.-M. Bussy communicated a note from M. Lefranc on atractylic acid; this acid occurs in Atractylis gummifera L. -MM. Schützenberger and Risler sent a paper on the oxidising power of blood.-The eighth note of M. P. Bert on experimental researches on the effect of changes of barometric pressure on life, was received.-M. Laboulbène communicated a note on the cause of the elevation of central tempera- | ture in cases of acute pleurisy, &c.-M. E. Rivière sent a note on the pre-historic station of Cape Roux.-From M. Champouillon a note on certain imperfections in the official report on recruiting in France was received.-M. Guerin sent a note on silkworm disease; he finds that both healthy and unhealthy moths lay sound eggs. Feb. 24.-M. de Quatrefages, president, in the chair.-M. Pasteur read a note on M. Cornalia's report on silkworm cultivation. M. Pasteur believes that his system of preserving the healthy eggs will produce good results..-M. Dumas reported on Mr. Fayrer's book on Indian poison snakes.-M. J. Raulin presented a paper on the silkworm disease, and M. Hugo a note on a necklace of polyhedric beads in the Louvre. M. Ed. Weyer a note on left-handed curves of the sixth order. M. de Rebaucour on the cyclic systems, MM. Troost and Hautefeuille on the The "solution" of gases in cast and wrought iron and in steel. authors believe that the gases given off in the "boiling" of iron are due to decompositions in the iron itself.-M. Ch. Violette sent a note on the compound of sugar with potassic chloride, and M. Grimaux one on the solidifying points of solutions of acetic anhydride in water.-M. Bidaud sent a note on the flame reaction of boric anhydride. He finds it to be excessively deli. cate, with a coal-gas bunsen flame.-M. L. Ranvier sent a paper on the regeneration of cut nerves. - MM. D. Tommasi and G. Quesneville on the action of zinc on acetylic chloride; M. ↑ Perry, notes on the third ray in triple refracting crystals and o the variability of the co-efficient of elasticity and dispersion. DIARY THURSDAY, MARCH 6. ROYAL SOCIETY, at 8.30.-On the Vapour Density of Potassium: J. Devar FRIDAY, MArch 7. ROYAL INSTITUTION, at 3.-On the Temperature of the Sun and the Work of Sunlight: James Dewar. GEOLOGISTS' ASSOCIATION, at 8-On the Geology of Brighton: James ROYAL INSTITUTION, at 3.-On the Philosophy of the Pure Sciences: Prof SUNDAY LECTURE SOCIETY, at 4-The Education of Women: Mrs. MONDAY, MARCH 10. ROYAL COLLEGE OF SURGEONS, at 4.-Extinct Mammals: Prof. Flower. CANTOR LECTURES, at 3.-On the Energy of Light, with especial reference to the Measurement and Utilisation of it: Rev. Arthur Rigg. TUESDAY, MARCH 11. PHOTOGRAPHIC SOCIETY, at 8.-On the Development of Negatives and SOCIETY OF ARTS, at 8.-On Signalling at Sea, with special reference to GEOLOGICAL SOCIETY, at 8-On the Solfatara and some Sul, hur-deposits at Kalamaki, near Corinth: Prof. Ansted. On the Origin of Clay-ironstone : J. Lucas.-Note in vindication of Leptophlæum rhombicum and Lepidodendron gaspianum: Principal Dawson-Synopsis of the younger formations of New Zealand: Captain F W. Hutton ARCH.EOLOGICAL ASOCIATION, at 8. LONDON INSTITUTION, at 7.- Fresco and Siliceous Painting: Prof Barff. ROYAL COLLEGE OF SURGEONS, at 4.-Extinct Mammals: Prof. Flower. BOOKS RECEIVED ENGLISH.-The Student's Manual of Comparative Anatomy and Guide to Dissection, Part 1, Mammalia: G. H. Morrell, MA -The Romance of Astronomy: R. K. Miller (Macmillan)-Colymbia (Trübner)-A Course of Qualitative Chemical Analysis: W. G. Valentin (Churchill).-Exalted States of the Nervous System. 3rd Edition: R. H. Collyer (Renshaw'.-The Story of the Earth and Man: J. W Dawson (Hodder and Stoughton), FOREIGN-Einleitung in die Theoretische Physik : V. Von Lang (Williams and Norgate). THURSDAY, MARCH 13, 1873 HERBERT SPENCER'S PSYCHOLOGY* The Principles of Psychology. By Herbert Spencer. Second edition. (Williams and Norgate.) Ο II. To the healthy scientific mind the fine-spun arguments and the wonderful logical achievements of metaphysicians are at once so bewildering and so distasteful that men of science can scarcely be got to listen even to those who would undertake to show that the arguments are but cobwebs, the logic but jingle, and the seeming profundity little more than a jumble of incongruous ideas shrouded in a mist of words. Hence, it is hardly known that one of the two living thinkers who in philosophy stand head and shoulders above all their contemporaries, has put forth all his strength in a grand effort to demonstrate the baselessness, the inconsistency, the unreality of all anti-realistic metaphysics. The disciples of Berkeley and Hume, skilful in argument, and generally armed with a psychology superior to that of their antagonists, have hitherto gained easy victories over the hosts of theologians, who, confident in the truth of their cause, have stood forward, as one might say, unarmed and with naked breast, to fight for the reality of mind and matter. So easily and so invariably have the sceptics and idealists remained masters of the field against all-comers that they have agreed among themselves to regard realism as an exploded superstition "altogether unworthy of the name of philosophy" (Prof. Bain). But the end is not yet. They will have once more to look to their weapons. In Mr. Spencer realism has for the first time found a champion that can do it justice. Nothing behind the acutest idealist in subtlety and force of intellect, he brings to bear on the great metaphysical question of the reality of an external world a psychology as much superior to that of the idealists, as their mental science was superior to that of the divines they so easily vanquished. Of course we shall not attempt to sketch the argument that occupies nineteen chapters of Mr. Spencer's volume; which has for its groundwork his whole system of psychology, and on the issue of which he considers that his entire philosophy is at stake; for, in his own words, 'should the idealist be right, the doctrine of evolution is a dream." It may, however, not be altogether profitless to dip into this elaborate argument at one or two places. "The argument of the Realist," says Mr. Spencer, "habitually fails from not having as a fulcrum some universally-admitted truth which the Idealist also has to admit." This necessary fulcrum, he alleges, is to be found in the Universal Postulate, which is, that we must accept as true that of which the negation cannot be represented in thought. But, it would almost seem no more easy to obtain universal assent to the doctrine, that the ultimate appeal must be to the inconceivableness of the negation of a proposition, than to establish the truth of realism by argument without the aid of such a fulcrum. At least, Mr. Mill and Mr. Spencer have been battling over this question for twenty years, without coming much nearer agreement than at the beginning. But though • Continued from p. 300. No. 176-VOL. VII. they may have done little towards their mutual instruction, many students of philosophy must have profited greatly from what they agree in describing as their "amicable controversy." And in venturing briefly to review the discussion, our justification must be that we do so as a disciple, who studies with reverence the works of both these imperial intellects. We shall first endeavour to outline in as few words as possible what appears to us an important part of Mr. Spencer's argument, leaving his full meaning to become apparent when we proceed to notice some of Mr. Mill's strictures thereon. Propositions, says Mr. Spencer, “are the ultimate components of knowledge. The simplest intuition equally with the most complex rational judgment, has the same fundamental structure: it is the tacit or overt assertion that something is or is not of a certain nature-belongs or does not belong to a certain class-has or has not a certain attribute." "Propositions, then, constitute the common denomination to which all systems of belief, simple or complex, have to be reduced before we can scientifically test them." But propositions are of many kinds; some are relatively simple, some are highly complex. "There are some propositions which tacitly assert little more than they avowedly assert; while there are other propositions in which what is tacitly asserted immensely exceeds in amount what is avowedly asserted." Accordingly, to "compare conclusions with scientific rigour, we must not only resolve arguments into their constituent propositions, but must resolve each complex proposition into the simple propositions composing it." When intelligence is thus resolved into its simplest elements, it is found that there are cognitions of which the terms cannot be separated. Such cognitions we necessarily accept. To ascertain that the predicate of a cognition invariably exists along with its subject, all we can do is to make a deliberate and persistent effort to conceive the negation of the proposition, and having done this, "to assert the inconceivableness of its negation, is at the same time to assert the psychological necessity we are under of thinking it, and to give our logical justification for holding it to be unquestionable." Further, as it is only by the aid of cognitions of this class, and for the trustworthiness of which no higher warrant can be given, that propositions are linked together so as to form what we call proof or disproof, since "logic is simply a systematisation of the process by which we indirectly obtain this warrant for beliefs that do not directly possess it," it must follow that an attempt to invalidate a cognition of this class by a process of reasoning must somewhat resemble the mechanical absurdity of trying to lift the chair on which one sits. Now, the belief that a universe exists apart from and independently of our states of consciousness, is, according to Mr. Spencer, a cognition possessing this quality of highest certainty. When a man looks at a book without speculating, “he feels that the sole content of his consciousness is the book considered as an external reality, . . . he feels that do what he will he cannot reverse this act; . . . while he continues looking at the book, his belief in it as an external reality possesses the highest validity. It has the direct guarantee of the Universal Postulate." Against this Mr. Mill has argued that the proposed warrant of the truth of propositions cannot be accepted, if for no other reason, because we know as a matter of X history that some propositions the negation of which was at one time inconceivable are now known to be false. His examples are-that in sunrise and sunset, it is the sun that moves; that gravitation cannot act through space absolutely void; and that there cannot exist antipodes-men sticking on by their feet to the under side of the earth. For the truth of each of these propositions Mr. Mill thinks that our forefathers had the warrant of what Mr. Spencer calls the Universal Postulate. "To this criticism of Mr. Mill," says Mr. Spencer, referring to the first and last of these propositions, "my reply is that the propositions erroneously accepted because they seemed to withstand the test, were complex propositions to which the test is inapplicable." Unfortunately, in his anxiety to "leave no possibility of misapprehension," Mr. Spencer mentioned, among other things, that we cannot by simple comparison of two states of consciousness know that the square of the hypothenuse of a rightangled triangle equals the sum of the squares of the other two sides. The strange result has been that Mr. Mill has, we cannot help thinking, fallen into a complete misapprehension of his meaning. In the eighth edition of his Logic, Mr. Mill has had the opportunity of replying to Mr. Spencer's argument as it stands in the volu me before us. He there says: "It is but just to give Mr. Spencer's doctrine the benefit of the limitation he claimsviz. that it is only applicable to propositions which are assented to on simple inspection, without any intervening media of proof. . . . But in all the three cases which I have just cited (those mentioned), the inconceivability seems to be apprehended directly; no train of argument is needed, as in the case of the square of the hypothenuse, to obtain the verdict of consciousness on the point." We submit that the quality of being “assented to on simple inspection, without any intervening media of proof" is not the distinguishing characteristic of what Mr. Spencer calls a simple proposition. The propositions that can be properly brought to the test of the inconceivableness of their negation are not such as are assented to on simple inspection, but such as "are not further decomposable." Until this misconception on the part of Mr. Mill furnished conclusive evidence to the contrary, we were inclined to think that here, as elsewhere, Mr. Spencer had been needlessly tedious in stating and restating, illustrating and re-illustrating his meaning. That after all Mr. Mill should have so completely missed the true nature of his distinction of propositions into simple and complex is very remarkable. Had not Mr. Spencer declared that the propositions in dispute were examples of what he considered complex propositions? There is no intervening media of proof when we automatically interpret our sensations of sight into such a cognition as "There is an old man." Yet this is one of the propositions tediously analysed by Mr. Spencer, "to show distinctly the number of propositions included in an ordinary proposition which appears simple. Again, "On a cold winter's night a gas-light seen through the window of a cab, or a light in a shop looked at through a pane that has been much rubbed, is surrounded by a halo. Whoever examines will see that this halo is caused by scratches on the glass, the curves of which are arcs of circles having the light for their centre. The proposition which expresses the result of his observation, and seems to assert no more than the result of his observation, is that on the part of the glass through which he looks the scratches produced by rubbing are arranged concentrically with the light." Included in this apparently simple proposition, however, is this other-" that there does not exist on the same spot scratches otherwise arranged, immeasurably exceeding in number the concentric scratches." The truth is that "the scratches on any part of the glass have no concentric arrangement at all, but run in countless directions with multitudinous curva. tures." The propositions in question obviously belong to this class. In the assertion, the sun moves from east to west, there is included the other proposition-the earth does not revolve on its axis from west to east. We scarcely think that Mr. Mill will assert that any human being ever found it impossible to conceive, in Mr. Spencer's sense, that a sphere should so revolve. Thus far, then, we are bound to say that Mr. Spencer's argument remains intact. With regard to gravitation we cannot do better than quote the note in which Mr. Mill replies to Mr. Spencer on this point : "In one of the three cases, Mr. Spencer, to my no small surprise, thinks that the belief of mankind 'cannot be rightly said to have undergone' the change I allege. Mr. Spencer still thinks we are unable to conceive gravitation acting through empty space. If an astronomer vowed that he could conceive gravitative force as exercised through space absolutely void, my private opinion would implies representation. Here the elements of the reprebe that he mistook the nature of conception. Conception sentation are the two bodies and an agency by which either effects the other. To conceive this agency is to represent it in some terms derived from our experiencesthat is from our sensation. As this agency gives us no sensations, we are obliged (if we try to conceive it) to use symbols idealised from our sensations-imponderable units forming a medium.' If Mr. Spencer means that the action of gravitation gives us no sensations, the assertion is one than which I have not seen, in the writings of philosophers, many more startling. What other sensation do we need than the sensation of one body moving towards another? The elements of the representation are not two bodies and an agency,' but two bodies and an effect; viz. the fact of their approaching one another. If we are able to conceive a vacuum, is there any difficulty in conceiving a body falling to the earth through it?" We are compelled to say that Mr. Mill could not have been much more surprised at Mr. Spencer's statement than we are at his answer. What was it that Newton could not conceive, but which, Mr. Mill says, we have no difficulty in conceiving? Was Newton incapable of forming a mental representation of "one body moving towards another?"-an experience that in common with everybody else, he had hundreds of times every day of his life. No. To put it in plain rough language, he was unable to conceive how one body could move another without in some way pushing or pulling at it. Hence, when he tried to represent in thought the action of the sun upon the earth he found it necessary to imagine a medium-an unbroken line of physical connection between the two bodies. Have we got beyond Newton in this respect? or is it not rather, as Mr. Spencer says, that our scientific men have simply "given up attempting to conceive how gravitation results." Nay, are there not |