“The task of unveiling the hidden truth demands some knowledge of Cosmogenesis, of the emanation of the Universe from the Absolute, the finite from the Infinite, and of the successive cycles, major and minor, of involution and evolution. In addition, both knowledge of the Symbolical Language, its purposes, methods and classical symbols, and the faculty of analysing and interpreting historical metaphors, are necessary to open the casket containing the treasures of concealed wisdom—the Holy Bible itself.”

Source: Milennial Dawn, Vol. III: Thy Kingdom Come (1891), pp. 314-5.

On the Uses and Transformations of Linear Algebra (1875)
Context: The familiar proposition that all A is B, and all B is C, and therefore all A is C, is contracted in its domain by the substitution of significant words for the symbolic letters. The A, B, and C, are subject to no limitation for the purposes and validity of the proposition; they may represent not merely the actual, but also the ideal, the impossible as well as the possible. In Algebra, likewise, the letters are symbols which, passed through a machinery of argument in accord ance with given laws, are developed into symbolic results under the name of formulas. When the formulas admit of intelligible interpretation, they are accessions to knowledge; but independently of their interpretation they are invaluable as symbolical expressions of thought. But the most noted instance is the symbol called the impossible or imaginary, known also as the square root of minus one, and which, from a shadow of meaning attached to it, may be more definitely distinguished as the symbol of semi-inversion. This symbol is restricted to a precise signification as the representative of perpendicularity in quaternions, and this wonderful algebra of space is intimately dependent upon the special use of the symbol for its symmetry, elegance, and power.

Part 2: "The Habit of Truth", §6 (p. 36)
Science and Human Values (1956, 1965)

Source: The Humans

Concluding Paragraph
On Practice (1937)
Original: (zh-CN) 通过实践而发现真理，又通过实践而证实真理和发展真理。从感性认识而能动地发展到理性认识，又从理性认识而能动地指导革命实践，改造主观世界和客观世界。实践、认识、再实践、再认识，这种形式，循环往复以至无穷，而实践和认识之每一循环的内容，都比较地进到了高一级的程度。这就是辩证唯物论的全部认识论，这就是辩证唯物论的知行统一观。

Pearls of Wisdom

Source: Ink and Bone

[1993, The Transcendent Unity of Religions, Quest Books, xxxi, 978-0-8356-0587-8]
Miscellaneous, Religion

Reported in Josiah Hotchkiss Gilbert, Dictionary of Burning Words of Brilliant Writers (1895), p. 275.