T. 17.—Called on Hugh Blackburn to talk about Cambridge.

W. 18.—Called on Capt. Wemyss to talk of Cambridge, and Prof. Forbes called on me and had a talk on James’s studies, etc.

1850. 1st April.—James Clerk Maxwell came in full of Forbes’s recommendation of Trinity College above all others at Cambridge, and that Peterhouse was less expensive than Caius; that the latter is too full to admit of rooms, and freshmen are obliged to lodge out.

28th October.—I had a kind letter from Mr. C. M., from Glenlair, after placing his son James at Peterhouse. He has already distinguished himself at Edinburgh by papers on the compression of solids, and other scientific subjects, read for him at the Royal Society. His manners are very peculiar; but having good sense, sterling worth, and good humour, the intercourse with a College world will rub off his oddities. I doubt not of his becoming a distinguished man.

January 1851.—James Clerk Maxwell often comes in. He is full of genius. He went to Cambridge with Robert in October, R to Caius, James to Peterhouse; but he is “migrating” to Trinity, and I have no doubt he will be a distinguished Philosopher some day.

The winter of 1847 found us together in the classes of Forbes and Kelland, where he highly distinguished himself. With the former he was a particular favourite, being admitted to the free use of the class apparatus for original experiments. He lingered here behind most of his former associates, having spent three years at the University of Edinburgh, working (without any assistance or supervision) with physical and chemical apparatus, and devouring all sorts of scientific works in the library.[131] During this period he wrote two valuable papers, which are published in our Transactions, on The Theory of Rolling Curves and on The Equilibrium of Elastic Solids. Thus he brought to Cambridge, in the autumn of 1850, a mass of knowledge which was really immense for so young a man, but in a state of disorder appalling to his methodical private tutor.[132] Though that tutor was William Hopkins, the pupil to a great extent took his own way, and it may safely be said that no high wrangler of recent years ever entered the Senate-house more imperfectly trained to produce “paying” work than did Clerk Maxwell. But by sheer strength of intellect, though with the very minimum of knowledge how to use it to advantage under the conditions of the Examination, he obtained the position of Second Wrangler, and was bracketed equal with the Senior Wrangler in the higher ordeal of the Smith’s Prizes. His name appears in the Cambridge Calendar as Maxwell of Trinity, but he was originally entered at Peterhouse, and kept his first term there, in that small but most ancient foundation which has of late furnished Scotland with the majority of the professors of mathematics and natural philosophy, in her four universities.

To Lewis Campbell, Esq.

Glenlair, 26th April 1850.

As I ought to tell you of our departure from Edinburgh and arrival here, so I ought to tell you of many other things besides. Of things pertaining to myself there are these:—The tutor of Peterhouse has booked me, and I am booked for Peterhouse, but will need a little more booking before I can write Algebra like a book.

I suppose I must go through Wrigley’s problems and Paley’s Evidences in the same sort of way, and be able to translate when required Eurip. Iph. in Aulid. In the meantime I have my usual superfluity of plans.

1. Classics—Eurip. normal upper I phi. epsilon nu normal upper Alpha nu lamda for Cambridge. (I hope no Latin or Greek verses except for honours.) Greek Testament, Epistles, for my own behoof, and perhaps some of Cicero De Officiis or something else for Latin.

2. Mathematics—Wrigley’s Problems, and Trig, for Cambridge; properties of the Ellipsoid and other solids for practice with Spher. Trig. Nothing higher if I can help it.

3. Nat. Phil.—Simple mechanical problems to produce that knack of solving problems which Prof. Forbes has taught me to despise. Common Optics at length; and for experimental philosophy, twisting and bending certain glass and metal rods, making jellies, unannealed glass, and crystals, and dissecting eyes—and playing Devils.

4. Metaphysics—Kant’s Kritik of Pure Reason in German, read with a determination to make it agree with Sir W. Hamilton.

5. Moral Philosophy—Metaphysical principles of moral philosophy. Hobbes’ Leviathan, with his moral philosophy, to be read as the only man who has decided opinions and avows them in a distinct way. To examine the first part of the seventh chapter of Matthew in reference to the moral principles which it supposes, and compare with other passages.

But I question if I shall be able to overtake all these things, although those of different kinds may well be used as alternate studies.

I read in Edinburgh Wilson’s Poems to see what he used to be like, and how much he had improved since then. Did you finish Festus?[133] I had only two days to read it, so that I skipped part of the long speech and a good deal of the jollification, which I think the dullest part of the book.

The opening makes one think that it is to be an imitation of the book of Job, but you soon see that you have to do with a dreamy mortal without a profession, but vain withal, and a hero among women, a jolly companion of some men, admired of students for talking of things which he knows not, nor can know, having a so-called philosophy, an intuitive science, and an underived religion, and with all these not perfect, but needing more expanded views of the folly of strict virtue and outward decency, of the magnificence, nay, of the duty of sinning, and of the identity of virtue and vice, and of all opposites. He takes for his friend one whom Wilson calls a very poor devil, who has wonderful mechanical powers, but never attempts but once the supposed object of his visit to earth, namely, temptation. He takes a more rational view of affairs than Festus in general, but is so extremely refined from ordinary devils, that the only passage sufficiently characteristic for ordinary rapid readers to recognise is the sermon to the crowd, as the speech in Hell is quite raw. He has not such an absolute and intuitive sense of things as Festus, and does not change so much according to his company. He seems a sincere, good-natured, unselfish devil; while Festus is very changeable, solemn when alone, jolly when with the jolly, drunk with the drunk, open with Lucifer, reserved in good company, amorous with all women, talkative and serious with all angels and saints, stern towards the unfortunate, and in all his affections altogether selfish.

The book is said to have a plan, but no plot. The plan is an exposition of the state of a man’s mind after having gone through German metaphysics. It was one destitute of notions, and has now been convinced that all these notions are one and the same. It is neither meat, nor drink, nor rank, nor money, nor any common thing he wants: “he is sure it isn’t,” and he is sore troubled for want of some great thing to do; and when L——r starts into proximity he is the very being he wanted to speak to; “he knew who it would be,” and recognises him at once. An opportunity is thus given for showing two ways of thinking about things, and therein lies the matter of the book. This may be seen in L——r’s sermon and Festus’ prayer. To turn and get out of the confusion of this letter, pray let me hear your opinion of the book. It may be considered thus:—

1. People read the book and wonder, why?

It is not read for the sake of the story—that is plain; nor for the clearness with which certain principles are developed, nor for the consistency of the book, nor for the variety of the characters; there must therefore be something overpoweringly attractive to hold you to the book. Some say he has fine thoughts, sufficient to set up fifty poets; to which some may answer, Where are they? Read it in a spirit of cold criticism, and they vanish. There is not one that is not either erroneous, absurd, German, common, or Daft. Where lies the beauty? In the reader’s mind. The author has evidently been thinking when he wrote it, and that not in words, but inwardly. The benevolent reader is compelled to think too, and it is so great a relief to the reader to get out of wordiness that he can put up with insanity, absurdity, profanity, and even inanity, if by so doing he can get into rapport with one who is so transcendental, and yet so easy to follow, as the poet. When Galileo set his [lamp] a-swinging by breathing on it, his power lay in the relation between the interval of his breaths and the time of vibration; so in Festus the mind that begins to perceive that his train of thoughts is that of the poem is readily made to follow on. There are some passages where one breaks loose, especially the rhyming description of the subpoenaing of the planets, and the notion of the angel of the earth giving Festus a pair of bracelets, and the way in which F. improves his mind by travel.

... Beauty is attributed to an object when the subject anticipates pleasure in it. A true pleasure is a consciousness of the right action of the faculty or function or power. Happiness is the integral of pleasure, as wisdom is of knowledge.... Don't take all this about Festus for truth, as I don’t believe much of it, and I’ll maybe tell you a new story if you tell me one.

What of St. Peter, as compared with the Keys and with Bob?[134]

From Prof. Forbes.

Edinburgh, 4th May 1850.

My dear Sir—Professor Kelland, to whom your paper was referred by the Council E. S., reports favourably upon it, but complains of the great obscurity of several parts, owing to the abrupt transitions and want of distinction between what is assumed and what is proved in various passages, which he has marked in pencil, and which I trust that you will use your utmost effort to make plain and intelligible. It is perfectly evident that it must be useless to publish a paper for the use of scientific readers generally, the steps of which cannot, in many places, be followed by so expert an algebraist as Prof. Kelland;—if, indeed, they be steps at all and not assumptions of theorems from other writers who are not quoted. You will please to pay particular attention to clear up these passages, and return the MS. by post to Professor Kelland, West Cottage, Wardie, Edinburgh, so that he may receive it by Saturday the 11th, as I shall then have left town.—Believe me, yours sincerely,

James D. Forbes.

To L. Campbell, Esq.

[June? 1850]

As there has been a long truce between us since I last got a letter from you, and as I do not intend to despatch this here till I receive Bob’s answer with your address, I have no questions to answer, and any news would turn old by keeping, so I intend briefly to state my country occupations (otherwise preparation for Cambridge, if you please). I find that after breakfast is the best time for reading Greek and Latin, because if I read newspapers or any of those things, then it is dissipation and ruin; and if I begin with props, experiments, or calculations, then I would be continually returning on them. At first I had got pretty well accustomed to regular study with a Dictionary, and did about 120 lines of Eurip. a day, namely, 40 revised, 40 for to-day, and 40 for to-morrow, with the looking up of to-morrow’s words. As I am blest with Dunbar’s Lexicon, it is not very highly probable that I will find my word at all; if I do, it is used in a different sense from Dunbar’s (so much the better), and it has to be made out from the context (either of the author or the Dictionary). So much for regular study, which I have nearly forgot, for when I had got to the end of the first chorus I began to think of the rods and wires that I had in a box. They have entirely stopped Eurip., for I found that if I spent the best part of the day on him, and took reasonable exercise, I could not much advance the making of the apparatus for tormenting these wires and rods. So the rods got the better of the Lexicon. The observations on the rods are good for little till they are finished; they are of three kinds, and are all distinguished for accuracy and agreement among themselves.

Thus—a rod bent by a weight at the middle takes the form of a curve, which is calculated to be one of the fourth order. Let A C B be the rod bent by a weight at C. Mirrors fastened to it at A and B make known the changes of the inclination of the tangent to the rod there, and a lens at C projects an image of a copper scale of inches and parts from A to B, where it is observed, and so the deflection of the rod at C becomes known. Now the calculated value of the elasticity deduced from the deflection differs from that deduced from the observations on the mirrors by about StartFraction 1 Over 140 EndFraction of either, and as the deflection at C was about one fourth inch, the difference of the observed and calculated deflections is about StartFraction 1 Over 280 EndFraction of an inch, which is near enough for home-made philosophical instruments to go.

Thus you see I would run on about rods and wires, and weights, angles, and inches, and copper and iron, and silvered glass, and all sorts of practicalities. Where is now Eurip.?—Ay, where? On the top of the Lexicon, and behind bundles of observations and calculations. When will he come out? for he was a good soul after all, and wise (beg his pardon, wiser). For the rest I have been at Shakespeare and Cowper. I used to put Thomson and Cowper together (why?), and Thomson first; now they are reversed and far asunder.

As I suppose my occupations are not very like yours, I pray you send me an account of what Oxford notions you have got, either from Oxonians, books, or observation; and as, if I was to question you, you could but answer my questions, I leave you to question yourself and send me some of the answers.

The only regular College science that I have thought of lately is Moral Philosophy. Whether it is an Oxford science I know not; but it must be, if not taught, at least interesting; so I purpose to fill up this letter with unuttered thoughts (or crude), which, as they are crammed into words, may appear like men new waked from sleep, who leap in confusion into one another’s breeches, hardly fit to be seen of decent men. Then think not my words mad if their clothes fit them not, for they have not had an opportunity of trying them oh before.

There are some Moral Philosophers whose opinions are remarkable for their general truth and good sense, but not for their utility, fixity, or novelty.

They tell you that in all your actions you ought to be virtuous, that benevolence is a virtue, that lawful rulers ought to be obeyed, that a man should give ear to his conscience.

Others tell you of unalterable laws of right and wrong, of Eternal truth and the Everlasting fitnesses of things. Others of the duty of following nature, of every virtue between two vices (Aristot.), and of the golden mean. That a man should do what is best on the whole (1) for himself; (2) for other men only, and not himself; (3) for the whole universe, including himself, and so on. Now I think that the answers to the following questions should be separate parts of M. Ph.:—

1. What is man? This is the introduction, and is called statical or proper Metaphysics.

2. What are the laws of human action? Action being all that man does—thought, word, deed.

3. What are the motives of human actions?

4. What actions do men perform in preference to what others, and why?

5. What is the principle by which men judge some actions right, others wrong?

6. What do particular men think of this principle? What are their doctrines?

7. What is the best criticism of right and wrong, or what (to us) is absolute right?

8. What are the best motives of human actions?

9. How are these motives to be implanted without violating the laws of human action?

10. What might, or rather what will, mankind become after this has been effected?

Moral Philosophy differs from Nat. Phil, in this, that the more new things we hear of in Nat. Phil, the better; but in Mor. Phil, the old things are best, so that a common objection to Mor. Phil, is that everybody knows it all before. If a man tells you that tyranny and anarchy are bad things, and that a just and lawful government is a good thing, it sounds very fine, but only means that when men think the government bad from excess or defect they give it the name of tyranny and anarchy. The ancient virtue of Tyrannicide was a man’s determination to kill the king whenever he displeased him. Thus it is easy to call a dog a bad name to beat him for. But there are other parts of Mor. Phil, in which there are differences of opinion, such as the nature of selfishness, self-love, appetites, desires, and affections, disinterestedness (what a word for a rush at!), which belong to the first three questions, and so on. I have told you something (p. 129) of three laws which I had been considering. In all parts of Mor. Phil, these three laws seem to meet one, and in each system of Morals they take a different form. How, that I might not deceive myself in thinking that I was safe out of the hands of the philosophers who argue these matters, I have been looking into the books of Moralists the most opposed to one another, to see what it is that makes them differ, and wherein they agree. The three principles concerning the nature of man are continually changing their shape, so that it is not easy to catch them in their best shape, nevertheless:

Lemma: Metaphysics.—A man thinks, feels, and wills, and therefore Metaphysicians give him the three faculties of cognition, feeling, and conation.

Cognition is what is called Understanding, and is most thought of generally.

Feelings are pleasures, pains, appetites, desires, aversions, approval and disapproval, love, hate, and all affections.

Conations are acts of will, whatever they be.

Now to move a man’s will it is necessary to move his affections. (How? Wait!) For no convictions of the understanding will do, for a man does what he likes to do, not what he believes to be best for himself or others. The feelings can only be moved by notions coming through the understanding, for cognition is the only inlet of thoughts. Therefore, although it can be proved that self-love leads to all goodness, or, in other words, that goodness is happiness, and self loves happiness, yet it can also be proved that men are not able to act rightly from pure self-love; so that though self-love is a very fine theoretical principle, yet no man can keep it always in view, or act reasonably upon it. Now, most moralists take for granted that the end which men, good or bad, pursue is their own happiness, and that happiness, false or true, is the motive of every action, and that it is the only right motive. Others say that benevolence is the only virtue, and that any action not done expressly for the good of others is entitled to no praise.

Most of the ancients, and Hobbes among the moderns, are of the first opinion. Hutcheson and Brown (I think) are of the second, and call the first selfish Philosophers and the selfish school. A few consider benevolence to the whole universe as the proper motive of every action, but they all (says Macintosh) confound men’s motives with the criterion of right and wrong, the reason why a thing is right, and that which actually causes a man to do it. In every book on Moral Philosophy some reference is made to that precept or maxim, which is declared to be the spirit of the law and the prophets (see Matt. VII. 12), and the application of it is a good mark of the uppermost thoughts or mode of thinking of the author.

Hobbes lays down as the first agreement of men to secure their safety, that a man should lay down so much of his natural liberty with respect to others, as he wishes that other men should to him. Hobbes having shown that men, in what the poets and moralists call a state of nature (that is, of equality and liberty, and without government), must be in a state of war, every man against every other, and therefore of danger to every man, deduces the obligation of obeying the powers that be from the necessity of Power to prevent universal war. Adam Smith’s theory of Moral Sentiments (which is the most systematic next to Hobbes) is that men desire others to sympathise with them, and therefore do those things which may be sympathised with; that is, as Smith’s opponents say, men ought to be guided by the desire of esteem and sympathy. Not so. Smith does not leave us there, but I suppose you have read him, as he is almost the only Scotch Moral Philosopher.

As it is Saturday night I will not write very much more. I was thinking to-day of the duties of [the] cognitive faculty. It is universally admitted that duties are voluntary, and that the will governs understanding by giving or withholding Attention. They say that Understanding ought to work by the rules of right reason. These rules are, or ought to be, contained in Logic; but the actual science of Logic is conversant at present only with things either certain, impossible, or entirely doubtful, none of which (fortunately) we have to reason on. Therefore the true Logic for this world is the Calculus of Probabilities, which takes account of the magnitude of the probability (which is, or which ought to be in a reasonable man’s mind). This branch of Math., which is generally thought to favour gambling, dicing, and wagering, and therefore highly immoral, is the only “Mathematics for Practical Men,” as we ought to be. How, as human knowledge comes by the senses in such a way that the existence of things external is only inferred from the harmonious (not similar) testimony of the different senses. Understanding, acting by the laws of right reason, will assign to different truths (or facts, or testimonies, or what shall I call them) different degrees of probability. How, as the senses give new testimonies continually, and as no man ever detected in them any real inconsistency, it follows that the probability and credibility of their testimony is increasing day by day, and the more a man uses them the more he believes them. He believes them. What is believing? When the probability (there is no better word found) in a man’s mind of a certain proposition being true is greater than that of its being false, he believes it with a proportion of faith corresponding to the probability, and this probability may be increased or diminished by new facts. This is faith in general. When a man thinks he has enough of evidence for some notion of his he sometimes refuses to listen to any additional evidence pro or con, saying, “It is a settled question, probatis probata; it needs no evidence; it is certain.” This is knowledge as distinguished from faith. He says, “I do not believe; I know.” “If any man thinketh that he knoweth, he knoweth yet nothing as he ought to know.” This knowledge is a shutting of one’s ears to all arguments, and is the same as “Implicit faith” in one of its meanings. “Childlike faith,” confounded with it, is not credulity, for children are not credulous, but find out sooner than some think that many men are liars. I must now to bed, so good night; only please to write when you get this, if convenient, and state the probability of your coming here. We perhaps will be in Edinburgh when the Wise men are there. How you are invited in a corner of a letter by

James Clerk Maxwell.

Glenlair, 16th September 1850.

Professor W. Thomson has asked me[135] to make him some magne-crystallic preparations which I am now busy with. How, in some of these bismuth is required, which is not to be found either in Castle-Douglas or Dumfries. I have, therefore, thought fit to request you, and do now request you, during your transit through Edinburgh on your way here, to go either to Mr. Kemp’s establishment in Infirmary Street, beside the College, or to some other dealer in metals, and there purchase and obtain two ounces of metallic bismuth (called Regulus of Bismuth), either powder or lumpish—all one. Thus you may perceive that the end of this letter is in two ounces of Regulus of Bismuth, that is, the metal bismuth, which if you do bring it with you, will please me well. Not that I am turned chemist. By no means; but common cook. My fingers are abominable with glue and chalk, gum and flour, wax and rosin, pitch and tallow, black oxide of iron, red ditto and vinegar. By combining these ingredients, I strive to please Prof. Thomson, who intends to submit them to Tyndall and Knoblauch, who, by means of them, are to discover the secrets of nature, and the origin of the magne-crystallic forces.

Now, if by coming here you could turn me from a cook to a grammarian by an irresistible influence you would do well; but if you remember the way I used to translate at the Academy, distorting the Latin of Livy to mean what I had preconceived, you will understand that at first I had not only to find out what the author meant, but to become convinced that it could not be what I thought it was.

John Wilson’s lectures on Moral Philosophy do not improve on reconsideration; they become indistinct and are resolved into the excellence of happiness, the acquiredness of conscience, and general good-humour, philanthropy and phi iota lamda alpha gamma alpha theta iota alpha. Here is an outline of Abstract Mor. Phil.:—

1. The principles of the growth of the mind (that is, the acquisition of opinions, propensities, and abilities).

2. The principles of government (the governor suits his actions to the laws of the thing governed).

3. The principle of sympathy (sauce for goose is sauce for gander).

Out of these heads may one make something?

As it is bed-time, and I have to put the glue and oxide of iron into shape to-night, I must stop here, and remain in hope of seeing you soon (say when).