In existographies, John Stuart Mill (1806-1873) (IQ:185|#69) (Cattell 1000:180) [RGM:151|1,500+] (Gottlieb 1000:81) (Perry 80:6|Li) [HD:24] (FA:80) (GPhE:#) (GEcE:#) [CR:105] was an English child prodigy turned moral philosopher and political economist noted for his 1842 chemical emergent properties arguments and for his latter efforts to amalgam a justice + utility model of natural morality.
Theism | Deism | Atheism
Mill’s father James Mill had rejected revealed religion as contrary to reason, and after much thought found “no halting place in deism”, but for some time remained in a state of perplexity, until concluding that nothing could be known about the origin of things; this has been described thusly:
“My father’s religion was of the same kind with that of Lucretius: he regarded it with the feelings due not to mere mental delusion, but to a great moral evil. His standard of morals were Epicurean, inasmuch as it was utilitarian, taking as exclusive text of right and wrong, the tendency of actions to produce pleasure or pain.”
— John Mill (1873), Autobiography 
“I am one of the very few examples in this country, of one who has not thrown off religious belief, but never had it. I grew up in a negative state with regard to it. I looked upon the modern [religion] exactly as I did upon the ancient religion, as something which in no way concerned me.”
— John Mill (1873), Autobiography 
Mill declared his atheism, and that of his father, in a famous essay published posthumously. 
Nature | Utility | Religion
In the 1850s, Mill penned three essays on nature, utility, and religions: “Nature” (c.1852), “Utility of Religion” (c.1858), and “Theism” (c.1869), wherein, according to Francis Edgeworth (1881), he, supposedly, gives the dimly discerned notion of a “divine idea of a power tending to the greatest possible quantity of happiness”, or something along these lines. 
Utilitarianism | Justice + Utility
In the 1850s, following the publication of his influential Principles of Political Economy (1848), Mill penned two essays entitled “Justice” and “Utility”, which were then incorporated with some alterations and additions into his 1861 Utilitarianism, wherein he expanded on English jurist and philosopher Jeremy Bentham's 1789 ‘utilitarianism’ system of morality.
“There are few circumstances among those which make up the present condition of human knowledge, more unlike what might have been expected, or more significant of the backward state in which speculation on the most important subjects still lingers, than the little progress which has been made in the decision of the controversy respecting the criterion of right and wrong.”
— John Mill (1861), Utilitarianism (pg. 1)
Emergence | Chemical properties
In 1842, Mill, in his System of Logic, at some point, according to American anthropological neuroscientist Terrence Deacon, outlined the "first attempt to describe emergence", supposedly, by giving an account of chemical properties of chemical compounds, e.g. salt, and as distinguished from those of their component elements, e.g. sodium and chlorine.
Mill, according to Deacon, gives the idea of a chemical reaction phenomenon of producing so-called table salt (needed for life) by the contact of two toxic and dangerous substances, chlorine gas and sodium metal, in some way, could be the combinatorial logic that produced life from mere chemistry.  This interpretation by Deacon, to note, my be elaborated adumbration, being that although Mill does, in his System of Logic, mention salt in the context of acid alkali reactions, the above "emergence" re-interpretation is difficult to find, being that Mill does not use this term. 
English philosopher George Lewes 1875 ideas on “emergence”, supposedly, were influenced by Mill. 
See main: Natural moralityIn 1852, Mill, in his "Nature" essay, stated the following on Alexander Pope's 1734 An Essay of Man moral poetry work: 
“For how stands the fact? That, next to the greatness of these cosmic forces, the quality which most forcibly strikes everyone who does not avert his eyes from it is their perfect and absolute recklessness. They go straight to their end without regarding what or whom they crush on the road. Optimists, in their attempts to prove that ‘whatever is, is right,’ are obliged to maintain, not that nature ever turns one step from her path to avoid trampling us into destruction, but that it would be very unreasonable in us to expect that she should. Pope's ‘Shall gravitation cease when you go by?’ may be a just rebuke to anyone who should be so silly as to expect common human morality from nature. But if the question were between two men, instead of between a man and a natural phenomenon, that triumphant apostrophe would be thought a rare piece of impudence. A man who should persist in hurling stones or firing cannon when another man 'goes by,' and, having killed him, should urge a similar plea in exculpation, would very deservedly be found guilty of murder. In sober truth, nearly all the things which men are hanged or imprisoned for doing to one another are nature's every-day performances.”
The "slave stealing parable" of Zeno of Citium seems to come to mind here.
Mill is the classical example of a "parentally-created genius" or forced prodigy. He was the eldest son of the Scottish philosopher, historian, and economist James Mill and Harriet Burrow, and was educated by his father, with the advice and assistance of Jeremy Bentham (also a former child prodigy) and Francis Place. He was given an extremely rigorous upbringing, and was deliberately shielded from association with children his own age other than his siblings. His father, a follower of Bentham and an adherent of associationism, had as his explicit aim to create a genius intellect that would carry on the cause of utilitarianism and its implementation after he and Bentham had died.
He learned Greek at 3; wrote a treatise on the history of Rome at 6; reading Plato, etc. at 7; Latin, geometry, and algebra at 8; conic sections, spherical section, and Newtonian arithmetic; chemistry age 13 at the Royal Military College; at 14, chemistry, zoology, metaphysics, and logic at Montpellier University; law at 16 under John Austin.
Mill is a top six Cox-Buzan genius; he is one of the fabled "last persons to know everything"; he is also, supposedly, a split-brainer who “could write Greek with his left hand while writing Latin with his right.” 
Mill is one of the rare "successful" breeds of forced prodigy; he recounts, in his Autobiography (1873), his early education as follows: (Ѻ)
“I have no remembrance of the time when I began to learn Greek. I have been told that it was when I was three years old. My earliest recollection on the subject, is that of committing to memory what my father termed Vocables, being lists of common Greek words, with their signification in English, which he wrote out for me on cards. Of grammar, until some years later, I learnt no more than the inflexions of the nouns and verbs, but, after a course of vocables, proceeded at once to translation; and I faintly remember going through AEsop's Fables, the first Greek book which I read. The Anabasis, which I remember better, was the second. I learnt no Latin until my eighth year. At that time I had read, under my father's tuition, a number of Greek prose authors, among whom I remember the whole of Herodotus, and of Xenophon's Cyropaedia and Memorials of Socrates; some of the lives of the philosophers by Diogenes Laertius; part of Lucian, and Isocrates' ad Demonicum and ad Nicoclem. I also read, in 1813, the first six dialogues (in the common arrangement) of Plato, from the Euthyphron to the Theaetetus inclusive: which last dialogue, I venture to think, would have been better omitted, as it was totally impossible I should understand it. But my father, in all his teaching, demanded of me not only the utmost that I could do, but much that I could by no possibility have done. What he was himself willing to undergo for the sake of my instruction, may be judged from the fact, that I went through the whole process of preparing my Greek lessons in the same room and at the same table at which he was writing: and as in those days Greek and English lexicons were not, and I could make no more use of a Greek and Latin lexicon than could be made without having yet begun to learn Latin, I was forced to have recourse to him for the meaning of every word which I did not know. This incessant interruption, he, one of the most impatient of men, submitted to, and wrote under that interruption several volumes of his History and all else that he had to write during those years.(add)
The only thing besides Greek, that I learnt as a lesson in this part of my childhood, was arithmetic: this also my father taught me: it was the task of the evenings, and I well remember its disagreeableness. But the lessons were only a part of the daily instruction I received. Much of it consisted in the books I read by myself, and my father's discourses to me, chiefly during our walks. From 1810 to the end of 1813 we were living in Newington Green, then an almost rustic neighbourhood. My father's health required considerable and constant exercise, and he walked habitually before breakfast, generally in the green lanes towards Hornsey. In these walks I always accompanied him, and with my earliest recollections of green fields and wild flowers, is mingled that of the account I gave him daily of what I had read the day before. To the best of my remembrance, this was a voluntary rather than a prescribed exercise. I made notes on slips of paper while reading, and from these, in the morning walks, I told the story to him; for the books were chiefly histories, of which I read in this manner a great number: Robertson's histories, Hume, Gibbon; but my greatest delight, then and for long afterwards, was Watson's Philip the Second and Third. The heroic defence of the Knights of Malta against the Turks, and of the revolted provinces of the Netherlands against Spain, exited in me an intense and lasting interest. Next to Watson, my favourite historical reading was Hooke's History of Rome. Of Greece I had seen at that time no regular history, except school abridgments and the first two or three volumes of a translation of Rollin's Ancient History, beginning with Philip of Macedon. But I read with great delight Langhorne's translation of Plutarch. In English history, beyond the time at which Hume leaves off, I remember reading Burnet's History of his Own Time, though I cared little for anything in it except the wars and battles; and the historical part of the Annual Register, from the beginning to about 1788, when the volumes my father borrowed for me from Mr Bentham left off. I felt a lively interest in Frederic of Prussia during his difficulties, and in Paoli, the Corsican patriot; but when I came to the American war, I took my part, like a child as I was (until set right by my father) on the wrong side, because it was called the English side. In these frequent talks about the books I read, he used, as opportunity offered, to give me explanations and ideas respecting civilization, government, morality, mental cultivation, which he required me afterwards to restate to him in my own words. He also made me read, and give him a verbal account of, many books which would not have interested me sufficiently to induce me to read them of myself: among others, Millar's Historical View of the English Government, a book of great merit for its time, and which he highly valued; Mosheim's Ecclesiastical History, McCrie's Life of John Knox, and even Sewel's and Rutty's Histories of the Quakers. He was fond of putting into my hands books which exhibited men of energy and resource in unusual circumstances, struggling against difficulties and overcoming them: of such works I remember Beaver's African Memoranda, and Collins's account of the first settlement of New South Wales. Two books which I never wearied of reading were Anson's Voyage, so delightful to most young persons, and a Collection (Hawkesworth's, I believe) of Voyages round the World, in four volumes, beginning with Drake and ending with Cook and Bougainville. Of children's books, any more than of playthings, I had scarcely any, except an occasional gift from a relation or acquaintance: among those I had, Robinson Crusoe was preeminent, and continued to delight me through all my boyhood. It was no part however of my father's system to exclude books of amusement, though he allowed them very sparingly. Of such books he possessed at that time next to none, but he borrowed several for me; those which I remember are the Arabian Nights, Cazotte's Arabian Tales, Don Quixote, Miss Edgeworth's "Popular Tales," and a book of some reputation in its day, Brooke's Fool of Quality.
In my eighth year I commenced learning Latin, in conjunction with a younger sister, to whom I taught it as I went on, and who afterwards repeated the lessons to my father: and from this time, other sisters and brothers being successively added as pupils, a considerable part of my day's work consisted of this preparatory teaching. It was a part which I greatly disliked; the more so, as I was held responsible for the lessons of my pupils, in almost as full a sense as for my own: I however derived from this discipline the great advantage of learning more thoroughly and retaining more lastingly the things which I was set to teach: perhaps, too, the practice it afforded in explaining difficulties to others, may even at that age have been useful. In other respects, the experience of my boyhood is not favourable to the plan of teaching children by means of one another. The teaching, I am sure, is very inefficient as teaching, and I well knew that the relation between teacher and taught is not a good moral discipline to either. I went in this manner through the Latin grammar, and a considerable part of Cornelius Nepos and Caesar's Commentaries, but afterwards added to the superintendence of these lessons, much longer ones of my own.
In the same year in which I began Latin, I made my first commencement in the Greek poet with the Iliad. After I had made some progress in this, my father put Pope's translation into my hands. It was the first English verse I had cared to read, and it became one of the books in which for many years I most delighted: I think I must have read it from twenty to thirty times through. I should not have thought it worth while to mention a taste apparently so natural to boyhood, if I had not, as I think, observed that the keen enjoyment of this brilliant specimen of narrative and versification is not so universal with boys, as I should have expected both a priori and from my individual experience. Soon after this time I commenced Euclid, and somewhat later, algebra, still under my father's tuition.
From my eighth to my twelfth year the Latin books which I remember reading were, the Bucolics of Virgil, and the first six books of the Aeneid; all Horace except the Epodes; the Fables of Phaedrus; the first five books of Livy (to which from my love of the subject I voluntarily added, in my hours of leisure, the remainder of the first decade); all Sallust; a considerable part of Ovid's Metamorphoses; some plays of Terence; two or three books of Lucretius; several of the Orations of Cicero, and of his writings on oratory; also his letters to Atticus, my father taking the trouble to translate to me from the French the historical explanations in Mongault's notes. In Greek I read the Iliad and Odyssey through; one or two plays of Sophocles, Euripides, and Aristophanes, though by these I profited little; all Thucydides; the Hellenics of Xenophon; a great part of Demosthenes, AEschines, and Lysias; Theocritus; Anacreon; part of the Anthology; a little of Dionysius; several books of Polybius; and lastly Aristotle's Rhetoric, which, as the first expressly scientific treatise on any moral or psychological subject which I had read, and containing many of the best observations of the ancients on human nature and life, my father made me study with peculiar care, and throw the matter of it into synoptic tables. During the same years I learnt elementary geometry and algebra thoroughly, the differential calculus and other portions of the higher mathematics far from thoroughly: for my father, not having kept up this part of his early acquired knowledge, could not spare time to qualify himself for removing my difficulties, and left me to deal with them, with little other aid than that of books; while I was continually incurring his displeasure by my inability to solve difficult problems for which he did not see that I had not the necessary previous knowledge.
As to my private reading, I can only speak of what I remember. History continued to be my strongest predilection, and most of all ancient history. Mitford's Greece I read continually; my father had put me on my guard against the Tory prejudices of this writer, and his perversions of facts for the white-washing of despot, and blackening of popular institutions. These points he discoursed on, exemplifying them from the Greek orators and historians, with such effect that in reading Mitford my sympathies were always on the contrary side to those of the author, and I could, to some extent, have argued the point against him: yet this did not diminish the ever new pleasure with which I read the book. Roman history, both in my old favourite, Hooke, and in Ferguson, continued to delight me. A book which, in spite of what is called the dryness of its style, I took great pleasure in, was the Ancient Universal History, through the incessant reading of which I had my head full of historical details concerning the obscurest ancient people, while about modern history, except detached passages, such as the Dutch war of independence, I knew and cared comparatively little. A voluntary exercise, to which throughout my boyhood I was much addicted, was what I called writing histories. I successively imposed a Roman history, picked out of Hooke; an abridgment of the Ancient Universal History; a History of Holland, from my favourite Watson and from an anonymous compilation; and in my eleventh and twelfth year I occupied myself with writing what I flattered myself was something serious. This was no less than a history of the Roman Government, compiled (with the assistance of Hooke) from Livy and Dionysius: of which I wrote as much as would have made an octavo volume, extending to the epoch of the Licinian Laws. It was, in fact, an account of the struggles between the patricians and plebeians, which now engrossed all the interest in my mind which I had previously felt in the mere wars and conquest of the Romans. I discussed all the institutional point as they arose: though quite ignorant of Niebuhr's researches, I, by such lights as my father had given me, vindicated the Agrarian Laws on the evidence of Livy, and upheld to the best of my ability the Roman democratic party. A few years later, in my contempt of my childish efforts, I destroyed all these papers, not then anticipating that I could ever feel any curiosity about my first attempt at writing and reasoning. My father encouraged me in this useful amusement, though, as I think judiciously, he never asked to see what I wrote; so that I did not feel that in writing it I was accountable to any one, nor had the chilling sensation of being under a critical eye.”
Quotes | By
The following are quotes by Mill:
“The amount of eccentricity in a society has generally been proportional to the amount of genius, mental vigor, and moral courage it contained. That so few now dare to be eccentric marks the chief danger of the time.”
— John Mill (c.1860), Ranker (Ѻ) best quote (#2)
1. Deacon, Terrence W. (2011). Incomplete Nature: How Mind Emerged from Matter (pg. 148, 199-200). W.W. Norton & Co.
2. (a) Deacon, Terrence W. (2011). Incomplete Nature: How Mind Emerged from Matter (pg. 148). W.W. Norton & Co.
(b) Lewes, George H. (1875). Problems of Life and Mind (First Series) (pg. 412), 2, London: Trübner.
3. Bentsen, Cheryl. (1979). “The Brightest Kids”, New York Magazine (pgs. 36-40). Jun 18.
4. (a) Mill, John S. (1843). A System of Logic, Ratiocination and Inductive: Being a Connected View of the Principles of Evidence and the Methods of Scientific Investigation (salt, pg. 110, 294-95, 340). Harper & Brothers, 1904.
(b) A System of Logic – Wikipedia.
5. (a) Mill, John S. (c.1852). “Nature”, in: Three Essays on Religion (pgs. 3-68; Pope, pg. 28). Longmans, Green & Co., 1885.
(b) Stewart, Balfour and Tait, Peter G. (1875). The Unseen Universe: or Physical Speculations on a Future State (pg. 195). Macmillan.
6. (a) Mill, John S. (c.1852). “Nature”, in: Three Essays on Religion (pgs. 3-68; Pope, pg. 28). Longmans, Green & Co., 1885.
(b) Mill, John S. (c.1858). “Utility of Religion”, in: Three Essays on Religion (pgs. 69-134). Longmans, Green & Co., 1885.
(c) Mill, John S. (c.1869). “Theism”, in: Three Essays on Religion (pgs. 125-257). Longmans, Green & Co., 1885.
(d) Edgeworth, Francis Y. (1881). Mathematical Psychics: an Essay on the Application of Mathematics to the Moral Sciences (pgs. 11-12). C. Kegan Paul & Co.
7. List of atheist philosophers – Wikipedia.
8. (a) Mill, John S. (1873). The Autobiography of John Stuart Mill (pg. 43, pg. #). Longmans.
(b) Hecht, Jennifer M. (2003). Doubt: A History: The Great Doubters and Their Legacy of Innovation from Socrates and Jesus to Thomas (pg. 382). HarperOne.
● John Stuart Mill – Wikipedia.