Chapter 24

The hardly less startling hypothesis that the _Echinoderms_ are coalesced worms, on the other hand, appears to be open to serious objection. As a matter of anatomy, it does not seem to me to correspond with fact; for there is no worm with a calcareous skeleton, nor any which has a band-like ventral nerve, superficial to which lies an ambulacral vessel. And, as a question of development, the formation of the radiate _Echinoderm_ within its vermiform larva seems to me to be analogous to the formation of a radiate Medusa upon a Hydrozoic stock. But a Medusa is surely not the result of the coalescence of as many organisms as it presents morphological segments.

Professor Haeckel adduces the fossil _Crossopodia_ and _Phyllodocites_ as examples of the Annelidan forms, by the coalescence of which the Echinoderms may have been produced; but, even supposing the resemblance of these worms to detached starfish arms to be perfect, it is possible that they may be the extreme term, and not the commencement, of Echinoderm development. A pentacrinoid Echinoderm, with a complete jointed stalk, is developed within the larva of _Antedon_. Is it not possible that the larva of _Crossopodia_ may have developed a vermiform Echinoderm?

With respect to the Phylogeny of the _Arthropoda_, I find myself disposed to take a somewhat different view from that of Professor Haeckel. He assumes that the primary stock of the whole group was a crustacean, having that _Nauplius_ form in which Fritz Müller has shown that so many _Crustacea_ commence their lives. All the _Entomostraca_ arose by the modification of some one or other of these Naupliform "_Archicarida_." Other _Archicarida_ underwent a further metamorphosis into a _Zoaea_-form. From some of these "_Zoeopoda_" arose all the remaining Malacostracous _Crustacea_; while, from others, was developed some form analogous to the existing _Galeodes_, out of which proceeded, by gradual differentiation, all the _Myriapoda, Arachnida,_ and _Insecta_.

I should, be disposed to interpret the facts of the embryological history and of the anatomy of the _Arthropoda_ in a different manner. The _Copepoda_, the _Ostracoda_, and the _Branchiopoda_ are the _Crustacea_ which have departed least from the embryonic or _Nauplius_-forms; and, of these, I imagine that the _Copepoda_ represent the hypothetical _Archicarida_ most closely. _Apus_ and _Sapphirina_ indicate the relations of these Archaeocarids with the _Trilobita_, and the _Eurypterida_ connect the _Trilobita_ and the _Copepoda_ with the _Xiphosura_. But the _Xiphosura_ have such close morphological relations with the _Arachnida_, and especially with the oldest known Arachnidan, _Scorpio_, that I cannot doubt the existence of a genetic connection between the two groups. On the other hand, the _Branchiopoda_ do, even at the present day, almost pass into the true _Podophthalmia_, by _Nebalia_. By the _Trilobita_, again, the _Archicarida_ are connected with such _Edriophthalmia_ as _Serolis_. The _Stomapoda_ are extremely modified _Edriophthalmia_ of the amphipod type. On the other side, the _Isopoda_ lead to the _Myriapoda_, and the latter to the _Insecta_. Thus the Arthropod phylum, which suggests itself to me, is that the branches of the _Podophthalmia_, of the _Insecta_ (with the _Myriapoda_), and of the _Arachnida_, spring separately and distinctly from the Archaeocarid root--and that the _Zoaea_-forms occur only at the origin of the Podophthalmous branch.

The phylum of the _Vertebrata_ is the most interesting of all, and is admirably discussed by Professor Haeckel. I can note only a few points which seem to me to be open to discussion. The _Monorhina_, having been developed out of the _Leptocardia_, gave rise, according to Professor Haeckel, to a shark-like form, which was the common stock of all the _Amphirhina_. From this "Protamphirhine" were developed, in divergent lines, the true Sharks, Rays, and _Chimaerae_; the Ganoids, and the _Dipneusta_. The _Teleostei_ are modified _Ganoidei_. The _Dipneusta_ gave rise to the _Amphibia_, which are the root of all other _Vertebrata_, inasmuch as out of them were developed the first _Vertebrata_ provided with an amnion, or the _Protamniota_. The _Protamniota_ split up into two stems, one that of the _Mammalia_, the other common to _Reptilia_ and _Aves_.

The only modification which it occurs to me to suggest in this general view of the Phylogeny of the _Vertebrata_ is, that the "Protamphirhine" was possibly more ganoid than shark-like. So far as our present information goes the Ganoids are as old as the Sharks; and it is very interesting to observe that the remains of the oldest Ganoids, _Cephalaspis_ and _Pteraspis_, have as yet displayed no trace of jaws. It is just possible that they may connect the _Monorhina_, with the Sturgeons among the _Amphirhina_. On the other hand, the Crossopterygian Ganoids exhibit the closest connection with _Lepidosiren_, and thereby with the _Amphibia_. It should not be forgotten that the development of the Lampreys exhibits curious points of resemblance with that of the _Amphibia_, which are absent in the Sharks and Rays. Of the development of the _Ganoidei_ we have unfortunately no knowledge, but their brains and their reproductive organs are more amphibian than are those of the Sharks.

On the whole, I am disposed to think that the direct stem of ascent from the _Monorhina_ to the _Amphibia_ is formed by the Ganoids and the Mudfishes; while the Osseous fishes and the Sharks are branches in different directions from this stem.

What the _Protamniota_ were like, I do not suppose any one is in a position to say, but I cannot think that the thoroughly Lacertian _Protorosaurus_ had anything to do with them. The reptiles which are most amphibian in their characters, and therefore, probably, most nearly approach the _Protamniota_, are the _Ichthyosauria_ and the _Chelonia_.

That the _Didelphia_ were developed out of some ornithodelphous form, as Professor Haeckel supposes, seems to be unquestionable; but the existing Opossums and Kangaroos are certainly extremely modified and remote from their ancestors the "_Prodidelphia_," of which we have not, at present the slightest knowledge. The mode of origin of the _Monodelphia_ from these is a very difficult problem, for the most part left open by Professor Haeckel. He considers the _Prosimiae_, or Lemurs, to be the common stock of the _Deciduata_, and the _Cetacea_ (with which he includes the _Sirenia_) to be modified _Ungulata_. As regards the latter question, I have little doubt that the _Sirenia_ connect the _Ungulata_ with the _Proboscidea_; and none, that the _Cetacea_ are extremely modified _Carnivora_. The passage between the Seals and the _Cetacea_ by _Zeuglodon_ is complete. I also think that there is much to be said for the opinion, that the _Insectivora_ represent the common stock of the _Primates_ (which passed into them by the _Prosimiae_), the _Cheiroptera_, the _Rodentia_, and the _Carnivora_. And I am greatly disposed to look for the common root of all the _Ungulata_, as well, in some ancient non-deciduate Mammals which were more like _Insectivora_ than anything else. On the other hand, the _Edentata_ appear to form a series by themselves.

The latter part of this notice of the _Natürliche Schöpfungs-Geschichte_, brings so strongly into prominence the points of difference between its able author and myself, that I do not like to conclude without reminding the reader of my entire concurrence with the general tenor and spirit of the work, and of my high estimate of its value.

XII.

BISHOP BERKELEY ON THE METAPHYSICS OF SENSATION.[1]

Professor Fraser has earned the thanks of all students of philosophy for the conscientious labour which he has bestowed upon his new edition of the works of Berkeley; in which, for the first time, we find collected together every thought which can be traced to the subtle and penetrating mind of the famous Bishop of Cloyne; while the "Life and Letters" will rejoice those who care less for the idealist and the prophet of tar-water, than for the man who stands out as one of the noblest and purest figures of his time: that Berkeley from whom the jealousy of Pope did not withhold a single one of all "the virtues under heaven;" nor the cynicism of Swift, the dignity of "one of the first men of the kingdom for learning and virtue;" the man whom the pious Atterbury could compare to nothing less than an angel; and whose personal influence and eloquence filled the Scriblerus Club and the House of Commons with enthusiasm for the evangelization of the North American Indians; and even led Sir Robert Walpole to assent to the appropriation of public money to a scheme which was neither business nor bribery.[2]

[Footnote 1: "The Works of George Berkeley, D.D., formerly Bishop of Cloyne, including many of his Works hitherto unpublished, with Preface, Annotations, his Life and Letters, and an Account of his Philosophy." By A.C. Fraser. Four vols. Oxford: Clarendon Press. 1871.]

[Footnote 2: In justice to Sir Robert, however, it is proper to remark that he declared afterwards, that he gave his assent to Berkeley's scheme for the Bermuda University only because he thought the House of Commons was sure to throw it out.]

Hardly any epoch in the intellectual history of England is more remarkable in itself, or possesses a greater interest for us in these latter days, than that which coincides broadly with the conclusion of the seventeenth and the opening of the eighteenth century.

The political fermentation of the preceding age was gradually working itself out; domestic peace gave men time to think; and the toleration won by the party of which Locke was the spokesman, permitted a freedom of speech and of writing such as has rarely been exceeded in later times.

Fostered by these circumstances, the great faculty for physical and metaphysical inquiry, with which the people of our race are naturally endowed, developed itself vigorously; and at least two of its products have had a profound and a permanent influence upon the subsequent course of thought in the world. The one of these was English Freethinking; the other, the Theory of Gravitation.

Looking back to the origin of the intellectual impulses of which these were the results, we are led to Herbert, to Hobbes, to Bacon; and to one who stands in advance of all these, as the most typical man of his time--Descartes. It is the Cartesian doubt--the maxim that assent may properly be given to no propositions but such as are perfectly clear and distinct--which, becoming incarnate, so to speak, in the Englishmen, Anthony Collins, Toland, Tindal, Woolston, and in the wonderful Frenchman, Pierre Bayle, reached its final term in Hume.

And, on the other hand, although the theory of Gravitation set aside the Cartesian vortices--yet the spirit of the "Principes de Philosophie" attained its apotheosis when Newton demonstrated all the host of heaven to be but the elements of a vast mechanism, regulated by the same laws as those which govern the falling of a stone to the ground. There is a passage in the preface to the first edition of the "Principia" which shows that Newton was penetrated, as completely as Descartes, with the belief that all the phenomena of nature are expressible in terms of matter and motion.

"Would that the rest of the phenomena of nature could be deduced by a like kind of reasoning from mechanical principles. For many circumstances lead me to suspect that all these phenomena may depend upon certain forces, in virtue of which the particles of bodies, by causes not yet known, are either mutually impelled against one another and cohere into regular figures, or repel and recede from one another; which forces being unknown, philosophers have as yet explored nature in vain. But I hope that, either by this method of philosophizing, or by some other and better, the principles here laid down may throw some light upon the matter."[1]

[Footnote 1: "Utinam caetera naturae phaenomena ex principiis mechanicis, eodem argumentandi genere, derivare licet. Nam multa me movent, ut nonnihil suspicer ca omnia ex viribus quibusdam pendere posse, quibus corporum particulae, per causas nondum cognitas, vel in se mutuo impelluntur et secundum figuras regulares cohaerent vel ab invicem fugantur et reced ent: quibus viribus ignotis, Philosophi hactenus Naturam frustra tentarunt. Spero autem quod vel huic philosophandi modo, vel veriori, alicui, principia hic posita lucem aliquam praebebunt."--Preface to First Edition of _Principia_, May 8, 1686.]

But the doctrine that all the phenomena of nature are resolvable into mechanism is what people have agreed to call "materialism;" and when Locke and Collins maintained that matter may possibly be able to think, and Newton himself could compare infinite space to the sensorium of the Deity, it was not wonderful that the English philosophers should be attacked as they were by Leibnitz in the famous letter to the Princess of Wales, which gave rise to his correspondence with Clarke.[1]

[Footnote 1: "Collection of Papers which passed between the late learned Mr. Leibnitz and Dr. Clarke."--1717.]

"1. Natural religion itself seems to decay [in England] very much. Many will have human souls to be material; others make God Himself a corporeal Being.

"2. Mr. Locke and his followers are uncertain, at least, whether the soul be not material and naturally perishable.

"3. Sir Isaac Newton says that space is an organ which God makes use of to perceive things by. But if God stands in need of any organ to perceive things by, it will follow that they do not depend altogether upon Him, nor were produced by Him.

"4. Sir Isaac Newton and his followers have also a very odd opinion concerning the work of God. According to their doctrine, God Almighty wants to wind up His watch from time to time; otherwise it would cease to move.[1] He had not, it seems, sufficient foresight to make it a perpetual motion. Nay, the machine of God's making is so imperfect, according to these gentlemen, that He is obliged to clean it now and then by an extraordinary concourse, and even to mend it as a clockmaker mends his work."

[Footnote 1: Goethe seems to have had this saying of Leibnitz in his mind when he wrote his famous lines--

"Was wär' ein Gott der nur von aussen stiesse Im Kreis das All am Finger laufen liesse."]

It is beside the mark, at present, to inquire how far Leibnitz paints a true picture, and how far he is guilty of a spiteful caricature of Newton's views in these passages; and whether the beliefs which Locke is known to have entertained are consistent with the conclusions which may logically be drawn from some parts of his works. It is undeniable that English philosophy in Leibnitz's time had the general character which he ascribes to it. The phenomena of nature were held to be resolvable into the attractions and the repulsions of particles of matter; all knowledge was attained through the senses; the mind antecedent to experience was a _tabula rasa_. In other words, at the commencement of the eighteenth century, the character of speculative thought in England was essentially sceptical, critical, and materialistic. Why "materialism" should be more inconsistent with the existence of a Deity, the freedom of the will, or the immortality of the soul, or with any actual or possible system of theology, than "idealism," I must declare myself at a loss to divine. But in the year 1700 all the world appears to have been agreed, Tertullian notwithstanding, that materialism necessarily leads to very dreadful consequences. And it was thought that it conduced to the interests of religion and morality to attack the materialists with all the weapons that came to hand. Perhaps the most interesting controversy which arose out of these questions is the wonderful triangular duel between Dodwell, Clarke, and Anthony Collins, concerning the materiality of the soul, and--what all the disputants considered to be the necessary consequence of its materiality--its natural mortality. I do not think that anyone can read the letters which passed between Clarke and Collins, without admitting that Collins, who writes with wonderful power and closeness of reasoning, has by far the best of the argument, so far as the possible materiality of the soul goes; and that, in this battle, the Goliath of Freethinking overcame the champion of what was considered Orthodoxy.

But in Dublin, all this while, there was a little David practising his youthful strength upon the intellectual lions and bears of Trinity College. This was George Berkeley, who was destined to give the same kind of development to the idealistic side of Descartes' philosophy, that the Freethinkers had given to its sceptical side, and the Newtonians to its mechanical side.

Berkeley faced the problem boldly. He said to the materialists: "You tell me that all the phenomena of nature are resolvable into matter and its affections. I assent to your statement, and now I put to you the further question, 'What is matter?' In answering this question you shall be bound by your own conditions; and I demand, in the terms of the Cartesian axiom, that in turn you give your assent only to such conclusions as are perfectly clear and obvious."

It is this great argument which is worked out in the "Treatise concerning the Principles of Human Knowledge," and in those "Dialogues between Hylas and Philonous," which rank among the most exquisite examples of English style, as well as among the subtlest of metaphysical writings; and the final conclusion of which is summed up in a passage remarkable alike for literary beauty and for calm audacity of statement.

"Some truths there are so near and obvious to the mind that a man need only open his eyes to see them. Such I take this important one to be, viz., that all the choir of heaven and furniture of the earth--in a word, all those bodies which compose the mighty frame of the world--have not any substance without a mind; that their being is to be perceived or known; that consequently, so long as they are not actually perceived by me, or do not exist in my mind or that of any other created spirit, they must either have no existence at all or else subsist in the mind of some eternal spirit; it being perfectly unintelligible, and involving all the absurdity of abstraction, to attribute to any single part of them an existence independent of a spirit."[1]

[Footnote 1: "Treatise concerning the Principles of Human Knowledge," Part I. § 6.]

Doubtless this passage sounds like the acme of metaphysical paradox, and we all know that "coxcombs vanquished Berkeley with a grin;" while common-sense folk refuted him by stamping on the ground, or some such other irrelevant proceeding. But the key to all philosophy lies in the clear apprehension of Berkeley's problem--which is neither more nor less than one of the shapes of the greatest of all questions, "What are the limits of our faculties?" And it is worth any amount of trouble to comprehend the exact nature of the argument by which Berkeley arrived at his results, and to know by one's own knowledge the great truth which he discovered--that the honest and rigorous following up of the argument which leads us to materialism, inevitably carries us beyond it.

Suppose that I accidentally prick my finger with a pin. I immediately become aware of a condition of my consciousness--a feeling which I term pain. I have no doubt whatever that the feeling is in myself alone; and if anyone were to say that the pain I feel is something which inheres in the needle, as one of the qualities of the substance of the needle, we should all laugh at the absurdity of the phraseology. In fact, it is utterly impossible to conceive pain except as a state of consciousness.

Hence, so far as pain is concerned, it is sufficiently obvious that Berkeley's phraseology is strictly applicable to our power of conceiving its existence--"its being is to be perceived or known," and "so long as it is not actually perceived by me, or does not exist in my mind, or that of any other created spirit, it must either have no existence at all, or else subsist in the mind of some eternal spirit."

So much for pain. Now let us consider an ordinary sensation. Let the point of the pin be gently rested upon the skin, and I become aware of a feeling or condition of consciousness quite different from the former--the sensation of what I call "touch." Nevertheless this touch is plainly just as much in myself as the pain was. I cannot for a moment conceive this something which I call touch as existing apart from myself, or a being capable of the same feelings as myself. And the same reasoning applies to all the other simple sensations. A moment's reflection is sufficient to convince one that the smell, and the taste, and the yellowness, of which we become aware when an orange is smelt, tasted, and seen, are as completely states of our consciousness as is the pain which arises if the orange happens to be too sour. Nor is it less clear that every sound is a state of the consciousness of him who hears it. If the universe contained only blind and deaf beings, it is impossible for us to imagine but that darkness and silence should reign everywhere.

It is undoubtedly true, then, of all the simple sensations that, as Berkeley says, their "_esse_ is _percipi_"--their being is to be "perceived or known." But that which perceives, or knows, is mind or spirit; and therefore that knowledge which the senses give us is, after all, a knowledge of spiritual phenomena.

All this was explicitly or implicitly admitted, and, indeed, insisted upon, by Berkeley's contemporaries, and by no one more strongly than by Locke, who terms smells, tastes, colours, sounds, and the like, "secondary qualities," and observes, with respect to these "secondary qualities," that "whatever reality we by mistake attribute to them [they] are in truth nothing in the objects themselves."

And again: "Flame is denominated hot and light; snow, white and cold; and manna, white and sweet, from the ideas they produce in us; which qualities are commonly thought to be the same in these bodies; that those ideas are in us, the one the perfect resemblance of the other as they are in a mirror; and it would by most men be judged very extravagant if one should say otherwise. And yet he that will consider that the same fire that at one distance produces in us the sensation of warmth, does at a nearer approach produce in us the far different sensation of pain, ought to bethink himself what reason he has to say that his idea of warmth, which was produced in him by the fire, is actually in the fire; and his idea of pain which the same fire produced in him in the same way, is not in the fire. Why are whiteness and coldness in snow, and pain not, when it produces the one and the other idea in us; and can do neither but by the bulk, figure, number, and motion of its solid parts?"[1]

[Footnote 1: Locke, "Human Understanding," Book II. chap. viii. §§ 14, 15.]

Thus far then materialists and idealists are agreed. Locke and Berkeley, and all logical thinkers who have succeeded them, are of one mind about secondary qualities--their being is to be perceived or known--their materiality is, in strictness, a spirituality.

But Locke draws a great distinction between the secondary qualities of matter, and certain others which he terms "primary qualities." These are extension, figure, solidity, motion and rest, and number; and he is as clear that these primary qualities exist independently of the mind, as he is that the secondary qualities have no such existence.