The Latin Rhetorica ad Herennium (author unknown) from the 90s BCE, calls these four operations ἔνδεια, πλεονασμός, μετάθεσις and ἐναλλαγή.
[1] Philo of Alexandria (c. 25 BCE – c. 50 CE), writing in Greek, listed the operations as addition (πρόσθεσις), subtraction (ἀφαίρεσις), transposition (μετάθεσις), and transmutation (ἀλλοίωσις).
"[17] In his book, A Handbook of Rhetorical Devices, author Robert A. Harris explains in depth, "Amplification involves repeating a word or expression while adding more detail to it, in order to emphasize what might otherwise be passed over.
In The Rhetoric, Aristotle contrasts amplification with depreciation and admits "they both derive from an enthymeme which serves to show how a thing is great or small.
"[19] The Princeton Encyclopedia of Poetry and Poetics also tells us that Cicero in De Oratore "introduced the confusion between amplification and attenuation by saying that the highest distinction of eloquence consists in amplification by means of ornament, which can be used to make one's speech not only increase the importance of a subject and raise it to a higher level, but also to diminish and disparage it".
Nevin Laib, author of Conciseness and Amplification explains that, "We need to encourage profuseness as well as concision, to teach not just brevity but also loquacity, the ability to extend, vary, and expatiate upon one's subject at length to shape, build, augment, or alter the force and effect of communication, and to repeat oneself inventively.
[20] Laib says, "The stylistic values implicit in our theories, pedagogy, and culture, so overwhelmingly favor conciseness, that elaboration gets lost in the learning process".
[20] Silva Rhetoricae provided by Gideon Burton of Brigham Young University understands amplification as something that can be used as a basic notion of imitation: to change the content of a model while retaining its form, or to change its form while retaining the content (varying a sentence; double translation; metaphrasis; paraphrasis; epitome).
[...] Classical rhetoric had already developed a theory of these kinds of intervention, drawing attention to the process of adaptation [...] If a topic had been treated by an earlier author, this was no reason to avoid it, but one had to try to emulate one's predecessor.
In short, the quadripartita ratio offered the student or author a ready-made framework, whether for changing words or the transformation of entire texts.