He was sent to the local schools, and gave evidence of unusual literary taste and ability. A small circulating library in the town, and a copy of the Encyclopædia Britannica which his father had purchased, furnished him with stores of reading of which he eagerly availed himself. Long afterwards he wrote of his early years--"Books, not playthings, filled my hands in childhood. At twelve I was deep, not only in poetry and fiction, but in encyclopaedias." Robert had been destined for the church, but this design had to be abandoned for lack of means. The family moved to Edinburgh in 1813, and in 1818 Robert began business as a bookstall-keeper in Leith Walk. He was then only sixteen, and his whole stock consisted of a few old books belonging to his father.
In 1819 his elder brother William had begun a similar business, and the two eventually united as partners in the publishing firm of W. & R. Chambers. Robert Chambers showed an enthusiastic interest in the history and antiquities of Edinburgh, and found a most congenial task in his Traditions of Edinburgh (2 vols., 1824), which secured for him the approval and the personal friendship of Sir Walter Scott. A History of the Rebellions in Scotland from 1638 to 1745 (5 vols., 1828) and numerous other works followed.
In the beginning of 1832 William Chambers started a weekly publication under the title of Chambers's Edinburgh Journal (known since 1854 as Chambers's Journal of Literature, Science and Arts), which speedily attained a large circulation. Robert was at first only a contributor. After fourteen numbers had appeared, however, he was associated with his brother as joint editor, and his collaboration contributed more perhaps than anything else to the success of the Journal.
Among the other numerous works of which Robert was in whole or in part the author, the Biographical Dictionary of Eminent Scotsmen (4 vols., Glasgow, 1832–1835), the Cyclopaedia of English Literature (1844), the Life and Works of Robert Burns (4 vols., 1851), Ancient Sea Margins (1848), the Domestic Annals of Scotland (1859–1861) and the Book of Days (2 vols., 1862–1864) were the most important.
Chambers's Encyclopaedia (1859–1868), with Dr Andrew Findlater as editor, was carried out under the superintendence of the brothers. The Cyclopaedia of English Literature contains a series of admirably selected extracts from the best authors of every period, "set in a biographical and critical history of the literature itself." For the Life of Burns he made diligent and laborious original investigations, gathering many hitherto unrecorded facts from the poet's sister, Mrs Begg, to whose benefit the whole profits of the work were generously devoted.
Robert Chambers was a scientific geologist, and availed himself of tours in Scandinavia and Canada for the purpose of geological exploration. The results of his travels were embodied in Tracings of the North of Europe (1851) and Tracings in Iceland and the Faroe Islands (1856). His knowledge of geology was one of the principal grounds on which the authorship of the Vestiges of the Natural History of Creation (2 vols., 1843–1846), was eventually assigned to him. The book was published anonymously, and daringly set out ideas of Lamarckian evolution. Robert Chambers was aware of the storm that would probably be raised at the time by a rational treatment of the subject, and did not wish to involve his firm in the discredit that a charge of heterodoxy would bring with it. The arrangements for publication were made through Alexander Ireland of Manchester, and the secret was so well kept that such different names as those of Prince Albert and Sir Charles Lyell were coupled with the book.
The book was a sensation, quickly becoming a best-seller and going into new editions. Charles Darwin admired its prose, but wrote that the "geology strikes me as bad, & his zoology far worse". By implying that God might not actively sustain the natural and social hierarchies, it threatened the social order and could provide ammunition to Chartists and revolutionaries. Anglican clergymen / naturalists attacked the book, with the geologist Adam Sedgwick predicting "ruin and confusion in such a creed" which if taken up by the working classes "will undermine the whole moral and social fabric" bringing "discord and deadly mischief in its train." The book was liked by many Quakers and Unitarians. The Unitarian physiologist William Carpenter called it "a very beautiful and a very interesting book", and helped Chambers with correcting later editions. Critics thanked God that the author began "in ignorance and presumption", for the revised versions "would have been much more dangerous". Vestiges brought widespread discussion of evolution which had previously been seen as a dangerous doctrine of street radicals, and hence paved the way for the publication of Darwin's theory of evolution by natural selection more than a decade later.
Chambers gave a talk on ancient beaches at the British Association for the Advancement of Science meeting at Oxford in May 1847. An observer at the meeting reported that Chambers "pushed his conclusions to a most unwarrantable length and got roughly handled on account of it by Buckland, De la Beche, Sedgwick, Murchison, and Lyell. The last told me afterwards that he did so purposely that [Chambers] might see that reasonings in the style of the author of the Vestiges would not be tolerated among scientific men." On the Sunday Samuel Wilberforce, Bishop of Oxford, used his sermon at St. Mary's Church on "the wrong way of doing science" to deliver a stinging attack obviously aimed at Chambers. The church "crowded to suffocation" with geologists, astronomers and zoologists heard jibes about the "half-learned" seduced by the "foul temptation" of speculation looking for a self-sustaining universe in a "mocking spirit of unbelief", showing a failure to understand the "modes of the Creator's acting" or to meet the responsibilities of a gentleman. Chambers denounced this as an attempt to stifle progressive opinion, but others thought he must have gone home "with the feeling of a martyr".
In 1851 Chambers was one of a group of writers who joined the publisher John Chapman in reinvigorating the Westminster Review as a flagship of freethought and reform, spreading the ideas of evolutionism.
Ireland in 1884 issued a 12th edition of Vestiges, with a preface giving an account of its authorship, which there was no longer any reason for concealing.
The Book of Days was Chambers's last publication, and perhaps his most elaborate. It was a miscellany of popular antiquities in connection with the calendar, and it is supposed that his excessive labour in connexion with this book hastened his death. Two years before, the university of St Andrews had conferred upon him the degree of doctor of laws, and he was elected a member of the Athenaeum Club in London. It is his highest claim to distinction that he did so much to give a healthy tone to the cheap popular literature which has become so important a factor in modern civilization.