“Even the existence of this corporeal element, low as it in reality is, because it is the source of death and all evils, is likewise good for the permanence of the Universe and the continuation of the order of things, so that one thing departs and the other succeeds.”

Source: Guide for the Perplexed (c. 1190), Part III, Ch.10

Commentary (p.92): Nichomacus is an idealist. He states his position in a way that recalls Plato's distinction between "that which ever exists, having no becoming" and "that which is ever becoming, never existent,"... On the one hand there are "the real things... which exist forever changeless and in the same way in the cosmos, never departing from their existence even for a brief moment," and on the other "the original eternal matter and substance" which was entirely "subject to deviation and change."
Nicomachus of Gerasa: Introduction to Arithmetic (1926)
Context: The ancients, who under the leadership of Pythagoras first made science systematic, defined philosophy as the love of wisdom... [Οἱ παλαιοὶ καὶ πρώτοι μεθοδεύσαντες ἐπιστήμην κατάρξαντος Πυθαγόρου ὡρίζοντο φιλοσοφίαν εἶναι φιλίαν σοφίας... ] This 'wisdom' he defined as the knowledge, or science, of the truth in real things, conceiving 'science' to be a steadfast and firm apprehension of the underlying substance. and 'real things' to be those which continue uniformly and the same in the universe and never depart even briefly from their existence; these real things would be things immaterial...<!--p.181

Source: Guide for the Perplexed (c. 1190), Part III, Ch.10

Source: Anti-Tech Revolution: Why and How (2016), p. 1

Draft for a Statement of Human Obligation (1943)
Context: There is a reality outside the world, that is to say, outside space and time, outside man's mental universe, outside any sphere whatsoever that is accessible to human faculties.
Corresponding to this reality, at the centre of the human heart, is the longing for an absolute good, a longing which is always there and is never appeased by any object in this world.
Another terrestrial manifestation of this reality lies in the absurd and insoluble contradictions which are always the terminus of human thought when it moves exclusively in this world.
Just as the reality of this world is the sole foundation of facts, so that other reality is the sole foundation of good.
That reality is the unique source of all the good that can exist in this world: that is to say, all beauty, all truth, all justice, all legitimacy, all order, and all human behaviour that is mindful of obligations.
Those minds whose attention and love are turned towards that reality are the sole intermediary through which good can descend from there and come among men.
Although it is beyond the reach of any human faculties, man has the power of turning his attention and love towards it.
Nothing can ever justify the assumption that any man, whoever he may be, has been deprived of this power.
It is a power which is only real in this world in so far as it is exercised. The sole condition for exercising it is consent.
This act of consent may be expressed, or it may not be, even tacitly; it may not be clearly conscious, although it has really taken place in the soul. Very often it is verbally expressed although it has not in fact taken place. But whether expressed or not, the one condition suffices: that it shall in fact have taken place.
To anyone who does actually consent to directing his attention and love beyond the world, towards the reality that exists outside the reach of all human faculties, it is given to succeed in doing so. In that case, sooner or later, there descends upon him a part of the good, which shines through him upon all that surrounds him.

The Talisman (1984)

Book I, ch. 18.
Discourses

Thoughts on Religion (1765), published posthumously