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NATURE 



\_Nov. 23, 1 87 1 



assure him (or it), however, that the omission has been in no way 

 connected with those "queer notions of honour, and justice, and 

 fairness," which he conceives to be rife in our times. Why should 

 I seek to wrong the honoured dead ? And who would gain in 

 this case by the injustice ? The present Astronomer Royal ? 

 Surely no. To add this small matter to his real claims to our 

 esteem would be 



To Gild refined gold, to paint the lily, 

 And throw a perfume on ihe violet. 



Neither, I am sure, has any other writer who has overlooked 

 Flamstead's claims, desired to do him injustice. On this point I 

 would merely remark, " Rest, rest, perturbed spirit." 



But now "we'll shift our ground," by the Ghost's good leave. 



Our visitor from Valhalla remarks that "a stir was lately 

 made about what was represented as a new method of investi- 

 gating the motion of the solar system in space, and instead of a 

 new there was brought forward an old acquaintance (known to 

 Science since the times of our grandfathers)." Here the spirit 

 of Flam'tead refers obviously to the Astronomer Royal's method. 

 I am sure that Prof. Airy would desire greatly that if his method 

 be indeed so ancient, the fact should be made widely known. 

 I myself am particularly anxious to be set right on this point, 

 about which I am at this veiy time writing. For though I care 

 more about explaining this and the other methods than about 

 their history, yet it is desirable to be accurate even in historical 

 details. 



If I may say so without offence, I would remark that a ghost 

 was not needed — certainly not the ghost of the first Astronomer 

 Royal — to teach astronomers that the opposition of Mars in 1S77 

 will be exceptionally important. At page 25 of my " Sun " I have 

 already pointed this out, and I dare say others have done likewise. 



I hope the "great injustice" to which our ghostly corre- 

 spondent refers as endured by him in life, does not relate to his 

 difficulties with Newton, for at the present time the opinion of 

 Brewster on this point is in vogue— not Daily's ; and the warmest 

 a dmirers of Flamstead are those who least desire to moot the 

 subject. R. A. Proctor 



Brighton, Nov. 4 



Creators of Science 



Permit me to do my little towards clearing up a most unfortu- 

 nate confusion of thought respecting the intellectual ranks of mathe- 

 maticians and metaphysicians, which is, in my experience, widely 

 prevalent. We may safely divide the mathematicians into three 

 orders : — (i) Inventors, (2) Experts, (3) Readers or Students, so 

 as to discriminate from one another those who create systems, 

 those who manipulate with them, as "ministers and interpreters 

 of nature" — just as easily and familiarly as Professor Tait(c^.) 

 employs and applies the theory of Quaternions — and those who 

 have merely studied into an understanding of an author or subject. 

 It was an expedient of the late Sir William Stirling Hamilton to 

 confound all these orders, and from the heterogeneous lump to 

 extract — if not extort — testimonies to the worthlessness of mathe- 

 matics as a mental discipline, without the least discrimination of 

 their sources. 



On the other hand, the metaphysicians cannot be trichotomised ; 

 for, even in the present advanced state of metaphysics, there is 

 no class of philosophers corresponding to the mathematical ex- 

 perts, the reason of which explains why examiners in mental science 

 do not set problems. There are, in fact, only two classes of meta- 

 physicians : I., Creators ; II., Students, more or less thoroughly 

 ver>ea in the systems of the leaders, and more or less accepting 

 or rejecting, with more or less reason, those creations. Accord- 

 ingly, when on May 17, 1869 (I tJiink that was the date), Pro- 

 fessor Tait, at a meeting of the Royal Society of Edinburgh, 

 challenged the metaphysical world to produce a metaphysician 

 who w.is also a mjthematician, he not being able at the moment 

 to call to mind a single instance, he was to be understood as 

 asking for a person of the order i, who was also in the class I. 

 Professor Calderwood's reply, then, was not wholly unexcep- 

 tionable, for of the three names he adduced, viz., Descartes, 

 Leibnitz, and Hegel, the last was that of a reader of mathematics, 

 and not of a iriathematical inventor. The challenger might have 

 spared the respondent the trouble of reply, had he known what 

 De Morgan wTote in Notes and Queries, 2iid S. vi. 293-4, where 

 are distinguished five mathematical inventors, z^/aciU' priucipt's : 

 viz., Archimedes, Gahleo, Descartes, Leibnitz, and Newton ; and 

 in which Aristotle, Plato, and D'Alembert are allowed a very 

 high rank in mathematics. Had the inventor of Quaternions 

 been then dead, I have little doubt that De Morgan would have 



added to the five the name of Sir William Rowan Hamilton, who, 

 besides being a maihetmtical inventor of the very first rank, was 

 also a diligent and accomplished student of Plato, Kant, Reid, 

 and the other Hamilton, and a writer on Logic ; /.(■., as good as 

 D'Ali-mbert as a philosopher, and perhaps better than he as a 

 mathematician. Now, it is not a little curious and very instruc- 

 tive to observe that, pace Platonu, the two who were creators of 

 strictly defined metaphysical svstems, viz., Descartes and Leibnitz, 

 are the only two among the five metaphysicians adduced by De 

 Morgan who belong to the highest rank as mathematical 

 inventors. 



It is quite incredible that a man of Professor Tait's learning 

 (I say here nothing of his judgment) should not have been aware 

 of the identity of Descartes (the poor dreamer I) and Carter, the 

 founder of the Cartesian Geometry ; still more so that he should 

 not have known that the immortal analyst, the co-inventor of 

 the Differential Calcidus, was the most eiriinent metaphysician 

 native to Germany before Kant. It was, then, not "ignorance," 

 but " ignoration," on the part of the Scotch mathematician, that 

 was involved in his challenge ; and that challenge was doubtless 

 intended as mere badinage, at the expense of a science which he 

 had taken no pains to understand. 



Be that as it may, I trust I am not singular in adjudging (as 

 De Morgan did) these two grand intellectual pursuits to be worthy 

 of being cultivated together, and to be able to give material aid 

 to each other. For rrryself, I cannot but look upon any man as 

 the enemy of intellectual progress, who delights in setting the 

 one class of investigators .against the other, and endeavours to 

 prolong the controversy which has raged between them since the 

 " Principia " was promulgated. 



Highgate, Nov. 8 C. M. Ingleby 



Descartes' "Animated Machines" 

 As you open your valuable coluirins to philosophieal discus- 

 sions, nray I request you to publish the following remarks on a 

 passa^,ein Mr. Lewe^'spopular "History of Philosophy" (Vol.ii.p. 

 i4Sof the new edition), where he confesses himself pirzzled, along 

 with other critics, to account for Descartes' theory that animals were 

 orAy animated machines. "I am not prepared," he says, "with 

 a satisfactory explanation." I cannot but tliink that a careful 

 peruialof the " Discourse on Method" (Part 5, snli.Jin.) and of 

 the treatise on les Passions de I'dme, makes Descartes' reasons 

 perfectly clear. In the first place, the use of the word machine 

 has misled most of his critics, and if the story of Malebranche and 

 his dog be true, even this great disciple had grievously mistaken 

 the principles of his master. For in the last-named treatise Des- 

 cartes endeavours to show that such feelings as joy, grief, fear, &c., 

 though in us accompanied by really mental acts (pensees), are 

 produced by physical causes, and produce physical effects apart 

 from the mind. Descartes worrld therefore never have detried 10 

 brutes .any of the bodily sensibilities which we possess ; and says 

 expressly that he calts them machines in a special sense — ma- 

 chines made by the Deity, and therefore infinitely more subtle 

 and ]ierfect than any which we can construct. He says that we 

 could not ourselves be ranked higher in the scale of beings did 

 we not possess the gift of iam^iia^e, the phenomena of which can 

 only be accounted for by an internal principle different in kind 

 from those which appear to guide the lower animals, though 

 there are also those passions in us which we have in common 

 with them. 



But to come to the psychological reasons for the theory. His- 

 torians of philosophy before the iSih century should be par- 

 ticularly alive to theological ido/a, even in sceptical writers ; much 

 more so in good Catholics like Descartes. Just as Berkeley put 

 forward prominently the theological advantages of his Idealism, 

 so Descartes indicates plainly in his "Discourse on Method" 

 {he. cit.) that these were the chief reasons of his theory. "Next 

 to the error of those who deny the Deity, whicli I have already 

 refuted, there is none more apt to seduce feeble minds fi-otn the 

 path o/virtne than to imagine that the soul of beasts is the same 

 as ours.'' But the locnsclassicns has, I think, escaped Mr Lewi.*^, 

 and will be found in a letter to a Lord (supposed to be the Duke 

 of Newcastle), the 54th of the 1st volume in the original quarto 

 editioir. Descartes there specially ans^vers objections made to him 

 on this point, and in the way above indicated ; adding however 

 the following passage : " Yet it may be said that although the 

 beasts perform no action which convinces us that they think, never- 

 thrless, as the organs of their bodies do not differ much from 01 rs, 

 it may be conjectured that some sort of thought is joined to these 

 organs, such as we experience in ourselves, but much less perfect ; 



