“Hence, as the line of sight to the upper part is the longer, it makes that part look as if it were leaning back. But when the members are inclined to the front, as described above, they will seem the beholder to be plumb and perpendicular.”

Source: Clockwork Prince

A Few Bits of Roman Mosaic.
Literary Essays, vol. I (1864-1890)

quote about the growing controversy between Mondrian and Van Doesburg. concerning the use of diagonal lines
Source: quote from a letter of Mondrian to Theo van Doesburg, undated, c. May 1918; as cited in Mondrian, -The Art of Destruction, Carel Blotkamp, Reaktion Books LTD. London 2001, p. 120

Preface, p. 43
The Divine Milieu (1960)

Ch 3 - p.68
Novels, Midwinter Break (2017)

Source: Desolation Road (1988), Chapter 18 (p. 94).

Letter to Hugo Boxel (Oct. 1674) The Chief Works of Benedict de Spinoza (1891) Tr. R. H. M. Elwes, Vol. 2, Letter 58 (54).
Context: Beauty, my dear Sir, is not so much a quality of the object beheld, as an effect in him who beholds it. If our sight were longer or shorter, or if our constitution were different, what now appears beautiful to us would seem misshapen, and what we now think misshapen we should regard as beautiful. The most beautiful hand seen through the microscope will appear horrible. Some things are beautiful at a distance, but ugly near; thus things regarded in themselves, and in relation to God, are neither ugly nor beautiful. Therefore, he who says that God has created the world, so that it might be beautiful, is bound to adopt one of the two alternatives, either that God created the world for the sake of men's pleasure and eyesight, or else that He created men's pleasure and eyesight for the sake of the world. Now, whether we adopt the former or the latter of these views, how God could have furthered His object by the creation of ghosts, I cannot see. Perfection and imperfection are names which do not differ much from the names beauty and ugliness.<!--p. 382

Source: It (1986)

The First Revelation, Chapter 8