In Book 1, Satan's speech to the other expelled angels in Hell can be seen as both a satire of militaristic rhetoric and an example of effective logos:
The mind is its own place, and in itself
Can make a Heav’n of Hell, a Hell of Heav’n.
What matter where, if I be still the same,
And what I should be, all but less than he
Whom thunder hath made greater? Here at least
We shall be free; th’ Almighty hath not built
Here for his envy, will not drive us hence:
Here we may reign secure, and in my choice
To reign is worth ambition though in Hell:
Better to reign in Hell, than serve in Heav’n.
The facetiousness of Satan's argument is immediately clear to the reader: the angels are literally surrounded by flames, and have essentially been locked into Hell. Thus, making a "Heav'n of Hell" seems virtually impossible. The angels are also not "free," as Satan declares, given that their fate has been sealed, and their punishment decided by God: Hell has become a prison for them.
By making Satan's statements so obviously duplicitous, Milton is satirizing the empty—yet elevated and ostentatious—rhetoric that military leaders, politicians, and monarchs employ to incite their followers. Language, Milton argues, is a powerful tool that can be exploited to manipulate others.
But Satan's cunning rhetoric is also an example of logos, since it is slyly persuasive: his argument is thoroughly reasoned, with clear premises and support. The angels can "reign secure" in Hell because God is unlikely to drive them out of Hell, having already confined them there; God's absence will allow them to organize themselves without interference. Moreover, Satan reminds the angels that the "mind is its own place"—that they still have sovereignty over their own minds, though they may be doomed to Hell (which is why they can understand Satan's argument as well). With this reframing, the angels' fall becomes part of Satan's own "choice," rather than a misfortune that has befallen him and his followers.
In Book 4, after Satan has approached Eve (in the form of a serpent), he employs logos to convince her to eat the forbidden fruit:
...Now I feel thy power
Within me clear, not only to discern
Things in their causes, but to trace the ways
Of highest agents, deemed however wise.
Queen of this universe, doe not believe
Those rigid threats of death; ye shall not die:
How should ye? by the fruit? it gives you life
To knowledge. By the Threat'ner? Look on me,
Me who have touch'd and tasted, yet both live,
And life more perfect have attained than Fate
Meant me, by vent'ring higher than my lot.
Satan is a cunning, skilled rhetorician: he begins his monologue by flattering Eve (calling her "Queen of this universe"), then employing logos to assuage her fears about eating the fruit and convince her that she is neither committing a wrongful act nor endangering herself.
Satan's logical reasoning is an example of sophistry—he has not tasted the forbidden fruit, and he is falsely representing himself as a serpent—but by clearly and logically delineating his argument (using himself as evidence for why she should not be afraid of eating the fruit), and framing Eve as a more powerful, righteous being than God (whom he labels the "Threat'ner"), he is able to persuade Eve to defy God's single prohibition.
In Book 9, Eve "muses" to herself in a soliloquy before deciding to eat the fruit from the Tree of Knowledge, using logos to support her decision:
Great are thy virtues, doubtless, best of fruits,
Though kept from man, and worthy to be admired,
Whose taste, too long forborne, at first assay
Gave elocution to the mute, and taught
The tongue not made for speech to speak thy praise:
Thy praise he also who forbids thy use,
Conceals not from us, naming thee the Tree
Of Knowledge, knowledge both of good and evil;
Forbids us then to taste, but his forbidding
Commends thee more, while it infers the good
By thee communicated, and our want:
For good unknown, sure is not had, or had
And yet unknown, is as not had at all.
Encouraged by Satan, Eve reasons that the fruit must be good, "though kept from man," because it miraculously conferred speech upon a formerly "mute" serpent. This inference is borrowed from Satan's own argument to Eve, in which he pretends that the fruit has given him the ability to speak. For Eve, this serves as evidence to justify her decision to seize the fruit: the serpent has not been punished for his decision, and therefore, Eve assumes she won't be, either. Moreover, Eve reasons that God's "forbidding," paradoxically, "commends" the fruit more. The fruit is so "good" that were she and Adam to know and enjoy its goodness, they would "want" it too badly; thus, God has prohibited them from eating the fruit in order to preserve it.
Eve also notes the Tree of Knowledge's ambiguous name, concluding that the fruit may not necessarily be harmful. The name suggests "knowledge both of good and evil," she says, which means that the fruit itself could confer divine knowledge of "good."
Unlike Satan, whose use of logos amounts to sophistry—a disingenuous argument intended to trick Eve—Eve is genuinely attempting to puzzle out why God might have placed this prohibition on her and Adam. Eve wants to reconcile what she already understands about the Tree—that "God hath pronounced it death to taste that Tree," as Adam reminds her—with what Satan has just told her: that the Tree's fruits have miraculous effects.
Though the reader is not always meant to sympathize with Eve, given the disastrous consequences of her transgression, this long soliloquy makes clear that Eve is thoughtful, curious, and reasonable—not simply rash and foolhardy. Her decision to eat the fruit has been thought-out and carefully considered, even if it is based on misleading temptation.
