“I tell you that if natural bodies have it from Nature to be moved by any movement, this can only be circular motion, nor is it possible that Nature has given to any of its integral bodies a propensity to be moved by straight motion. I have many confirmations of this proposition, but for the present one alone suffices, which is this. I suppose the parts of the universe to be in the best arrangement, so that none is out of its place, which is to say that Nature and God have perfectly arranged their structure. This being so, it is impossible for those parts to have it from Nature to be moved in straight, or in other than circular motion, because what moves straight changes place, and if it changes place naturally, then it was at first in a place preternatural to it, which goes against the supposition. Therefore, if the parts of the world are well ordered, straight motion is superfluous and not natural, and they can only have it when some body is forcibly removed from its natural place, to which it would then return by a straight line, for thus it appears that a part of the earth does [move] when separated from its whole. I said "it appears to us," because I am not against thinking that not even for such an effect does Nature make use of straight line motion.”

— Galileo Galilei

A note on this statement is included by Stillman Drake in his Galileo at Work, His Scientific Biography (1981): Galileo adhered to this position in his Dialogue at least as to the "integral bodies of the universe." by which he meant stars and planets, here called "parts of the universe." But he did not attempt to explain the planetary motions on any mechanical basis, nor does this argument from "best arrangement" have any bearing on inertial motion, which to Galileo was indifference to motion and rest and not a tendency to move, either circularly or straight.
Letter to Francesco Ingoli (1624)

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Galileo Galilei 70

Italian mathematician, physicist, philosopher and astronomer 1564–1642

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“After so many great men have worked on this subject, I almost do not dare to say that I have discovered the universal principle upon which all these laws are based, a principle that covers both elastic and inelastic collisions and describes the motion and equilibrium of all material bodies.
This is the principle of least action, a principle so wise and so worthy of the supreme Being, and intrinsic to all natural phenomena; one observes it at work not only in every change, but also in every constancy that Nature exhibits. In the collision of bodies, motion is distributed such that the quantity of action is as small as possible, given that the collision occurs. At equilibrium, the bodies are arranged such that, if they were to undergo a small movement, the quantity of action would be smallest.
The laws of motion and equilibrium derived from this principle are exactly those observed in Nature. We may admire the applications of this principle in all phenomena: the movement of animals, the growth of plants, the revolutions of the planets, all are consequences of this principle. The spectacle of the universe seems all the more grand and beautiful and worthy of its Author, when one considers that it is all derived from a small number of laws laid down most wisely. Only thus can we gain a fitting idea of the power and wisdom of the supreme Being, not from some small part of creation for which we know neither the construction, usage, nor its relationship to other parts. What satisfaction for the human spirit in contemplating these laws of motion and equilibrium for all bodies in the universe, and in finding within them proof of the existence of Him who governs the universe!”

Pierre Louis Maupertuis (1698–1759) French mathematician, philosopher and man of letters

Les Loix du Mouvement et du Repos, déduites d'un Principe Métaphysique (1746)

“Proposition I. Theorem I: When a projectile is carried in motion compounded from equable horizontal and from naturally accelerated downward [motions], it describes a semiparabolic line in its movement.”

Galileo Galilei (1564–1642) Italian mathematician, physicist, philosopher and astronomer

Author, Day Four, Stillman Drake translation (1974) p. 269
Dialogues and Mathematical Demonstrations Concerning Two New Sciences (1638)

“It seems to me proper to adorn the Author's thought here with its conformity to a conception of Plato's regarding the determination of the various speeds of equable motion in the celestial motions of revolution. …he said that God, after having created the movable celestial bodies, in order to assign to them those speeds with which they must be moved perpetually in equable circular motion, made them depart from rest and move through determinate spaces in that natural straight motion in which we sensibly see our moveables to be moved from the state of rest, successively accelerating. And he added that these having been made to gain that degree [of speed] which it pleased God that they should maintain forever, He turned their straight motion into circulation, the only kind [of motion] that is suitable to be conserved equably, turning always without retreat from or approach toward any pre-established goal desired by them. The conception is truly worthy of Plato, and it is to be more esteemed to the extent that its foundations, of which Plato remained silent, but which were discovered by our Author in removing their poetical mask or semblance, show it the guise of a true story.”

Galileo Galilei (1564–1642) Italian mathematician, physicist, philosopher and astronomer

I. Bernard Cohen's thesis: Galileo believed only circular (not straight line) motion may be conserved (perpetual), see The New Birth of Physics (1960).
Sagredo, Day Four, Stillman Drake translation (1974) pp.283-284
Dialogues and Mathematical Demonstrations Concerning Two New Sciences (1638)

“If… the motion of the earth were circular, it would be violent and contrary to nature, and could not be eternal, since … nothing violent is eternal …. It follows, therefore, that the earth is not moved with a circular motion.”

Thomas Aquinas (1225–1274) Italian Dominican scholastic philosopher of the Roman Catholic Church

Commentaria in libros Aristotelis de caelo et mundo

“And of universal nature, the notion I would offer, should be something like this. Nature is the aggregate of the bodies, that make up the world, in its present state, considered as a principle, by virtue whereof, they act and suffer, according to the laws of motion, prescribed by the author of things.”

Robert Boyle (1627–1691) English natural philosopher, chemist, physicist, and inventor

"A Free Inquiry into the Vulgar Notion of Nature" Sect.2 ibid.

“Whence do you have it that the terrestrial globe is so heavy? For my part, either I do not know what heaviness is, or the terrestrial globe is neither heavy nor light, as likewise all other globes of the universe. Heaviness to me (and I believe to Nature) is that innate tendency by which a body resists being moved from its natural place and by which, when forcibly removed therefrom, it spontaneously returns there. Thus a bucketful of water raised on high and set free, returns to the sea; but who will say that the same water remains heavy in the sea, when being set free there, does not move?”

Galileo Galilei (1564–1642) Italian mathematician, physicist, philosopher and astronomer

Letter to Francesco Ingoli (1624)

“In this way, the mansions arranged along either bank of the canal made one think of objects of nature, but of a nature which seemed to have created its works with a human imagination.”

Marcel Proust book In Search of Lost Time

Aussi, les demeures disposées des deux côtés du chenal faisaient penser à des sites de la nature, mais d'une nature qui aurait créé ses œvres avec une imagination humaine.
Source: In Search of Lost Time, Remembrance of Things Past (1913-1927), Vol. VI: The Sweet Cheat Gone (1925), Ch. III: Venise

“As the nature of the universal has given to every rational being all the powers that it has, so we have received from it this power also. For as the universal nature converts and fixes in its predestined place everything which stands in the way and opposes it, and makes such things a part of itself, so also the rational animal is able to make every hindrance its own material, and to use it for such purpose as it may have designed.”

Marcus Aurelius book Meditations

VIII, 35
Meditations (c. 121–180 AD), Book VIII

“There is… something which is in energy only; and there is something which is both in energy and capacity. …of relatives, one is predicated as according to excess and defect: another according to the effective and passive, and, in short, the motive, and that which may be moved… Motion, however, has not a substance separate from things… But each of the categories subsists in a twofold manner in all things. Thus… one thing pertaining to it is form, and another privation. …So the species of motion and mutation are as many as those of being. But since in every genus of things, there is that which is in entelecheia, and that which is in capacity; motion is the entelecheia of that which is in capacity… That there is energy, therefore, and that a thing then happens to be moved, when this energy exists, and neither prior nor posterior to it, is manifest. … [N]either motion nor mutation can be placed in any other genus; nor have those who have advanced a different opinion concerning it spoken rightly. …for by some motion is said to be difference, inequality, and non-being; though it is not necessary that any of these should be moved… Neither is mutation into these, nor from these, rather than from their opposites. …The cause, however, why motion appears to be indefinite, is because it can neither be simply referred to the capacity, nor to the energy of beings. …[I]t is difficult to apprehend what motion is: for it is necessary to refer it either to privation, or to capacity, or to simple energy; but it does not appear that it can be any of these. The above-mentioned mode, therfore remains, viz. that it is a certain energy; but… difficult to be perceived, but which may have a subsistence.”

Aristotle book Physics

Book III, Ch. I, pp. 137-147.
Physics

“In arranging the bodies in order of their electrical nature, there is formed an electro-chemical system which, in my opinion, is more fit than any other to give an idea of chemistry.”

Jöns Jacob Berzelius (1779–1848) Swedish chemist

Jöns Jacob Berzelius, Essai sur le théorie des proportions chimiques (1819). Translated in Henry M. Leicester and Herbert S. Klickstein, A Source Book in Chemistry 1400-1900 (1952), 260.

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Galileo Galilei 70

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