“In March 1879 Clifford died at Madeira; six years afterwards a posthumous work is for the first time placed before the public. …The original work as planned by Clifford was to have been entitled The First Principles of the Mathematical Sciences Explained to the Non-Mathematical, and to have contained six chapters, on Number, Space, Quantity, Position, Motion, and Mass respectively. Of the projected work Clifford in the year 1875 dictated the chapters on Number and Space completely, the first portion of the chapter on Quantity, and somewhat later nearly the entire chapter on Motion. The first two chapters were afterwards seen by him in proof, but never finally revised. Shortly before his death he expressed a wish that the book should only be published after very careful revision and that its title should be changed to The Common Sense of the Exact Sciences.”

The Structure of the Universe: An Introduction to Cosmology (1949)
Context: The models of Einstein and de Sitter are static solutions of Einstein's modified gravitational equations for a world-wide homogeneous system. They both involve a positive cosmological constant λ, determining the curvature of space. If this constant is zero, we obtain a third model in classical infinite Euclidean space. This model is empty, the space-time being that of Special Relativity.
It has been shown that these are the only possible static world models based on Einstein's theory. In 1922, Friedmann... broke new ground by investigating non-static solutions to Einstein's field equations, in which the radius of curvature of space varies with time. This Possibility had already been envisaged, in a general sense, by Clifford in the eighties.<!--p.82

Preface p. vi
A History of Greek Mathematics (1921) Vol. 1. From Thales to Euclid

Half Moon Investigations (2006)

1940 - 1950
Source: the catalogue of the 'Ideographic Picture' show, New York, 1947

Source: 1850s, An Investigation of the Laws of Thought (1854), p. 12; Cited in: Alexander Bain (1870) Logic, p. 191

Black on Broadway (2004)

Source: Lenin and Philosophy and Other Essays (1968), "Philosophy as a Revolutionary Weapon", p. 4

Vol. I, Ch. 11: Of the Times of the Birth and Passion of Christ
Observations upon the Prophecies of Daniel, and the Apocalypse of St. John (1733)
Context: John therefore baptized two summers, and Christ preached three. The first summer John preached to make himself known, in order to give testimony to Christ. Then, after Christ came to his baptism and was made known to him, he baptized another summer, to make Christ known by his testimony; and Christ also baptized the same summer, to make himself the more known: and by reason of John's testimony there came more to Christ's baptism than to John's. The winter following John was imprisoned; and now his course being at an end, Christ entered upon his proper office of preaching in the cities. In the beginning of his preaching he completed the number of the twelve Apostles, and instructed them all the first year in order to send them abroad. Before the end of this year, his fame by his preaching and miracles was so far spread abroad, that the Jews at the Passover following consulted how to kill him. In the second year of his preaching, it being no longer safe for him to converse openly in Judea, he sent the twelve to preach in all their cities: and in the end of the year they returned to him, and told him all they had done. All the last year the twelve continued with him to be instructed more perfectly, in order to their preaching to all nations after his death. And upon the news of John's death, being afraid of Herod as well as of the Jews, he walked this year more secretly than before; frequenting deserts, and spending the last half of the year in Judea, without the dominions of Herod.

Eine mathematische Theorie ist nicht eher als vollkommen anzusehen, als bis du sie so klar gemacht hast, daß du sie dem ersten Manne erklären könntest, den du auf der Straße triffst.
Mathematical Problems (1900)
Context: An old French mathematician said: A mathematical theory is not to be considered complete until you have made it so clear that you can explain it to the first man whom you meet on the street. This clearness and ease of comprehension, here insisted on for a mathematical theory, I should still more demand for a mathematical problem if it is to be perfect; for what is clear and easily comprehended attracts, the complicated repels us.