“The trouble with unknown enemies is that they are so difficult to identify.”
Elizabeth Peters The Hippopotamus Pool
Source: The Hippopotamus Pool
“The trouble with unknown enemies is that they are so difficult to identify.”
Elizabeth Peters The Hippopotamus Pool
Source: The Hippopotamus Pool
“A change of opinions is almost unknown in an elderly military man.”
G. K. Chesterton (1874–1936) English mystery novelist and Christian apologist
A Utopia of Usurers (1917)
Omar Khayyám (1048–1131) Persian poet, philosopher, mathematician, and astronomer
Treatise on Demonstration of Problems of Algebra (1070).
Context: By the help of God and with His precious assistance, I say that Algebra is a scientific art. The objects with which it deals are absolute numbers and measurable quantities which, though themselves unknown, are related to "things" which are known, whereby the determination of the unknown quantities is possible. Such a thing is either a quantity or a unique relation, which is only determined by careful examination. What one searches for in the algebraic art are the relations which lead from the known to the unknown, to discover which is the object of Algebra as stated above. The perfection of this art consists in knowledge of the scientific method by which one determines numerical and geometric unknowns.
Alexandre Kojève (1902–1968) Russian-born French philosopher and statesman
Source: Introduction to the Reading of Hegel: Lectures on the Phenomenology of Spirit, assembled by Raymond Queneau, edited by Allan Bloom, translated by James H. Nichols, Jr. (1969), Editor's Introduction