1. What is it?

Morality is the notion of doing the ‘right’ thing. This generally means acting with kindness towards others and rejecting a wicked course of action.

When morality is used as a theme in literature, it usually concerns a character having a choice between good and evil.

2. How is it made?

3. Examples in literature

Hamlet 
by William Shakespeare

Excerpt from Act III, Scene I:

Hamlet: To be, or not to be- that is the question:
Whether ’tis nobler in the mind to suffer
The slings and arrows of outrageous fortune
Or to take arms against a sea of troubles,
And by opposing end them. To die- to sleep-
No more; and by a sleep to say we end
The heartache, and the thousand natural shocks
That flesh is heir to. ‘Tis a consummation
Devoutly to be wish’d. To die- to sleep.
To sleep- perchance to dream: ay, there’s the rub!
For in that sleep of death what dreams may come
When we have shuffled off this mortal coil,
Must give us pause. There’s the respect
That makes calamity of so long life.
For who would bear the whips and scorns of time,
Th’ oppressor’s wrong, the proud man’s contumely,
The pangs of despis’d love, the law’s delay,
The insolence of office, and the spurns
That patient merit of th’ unworthy takes,
When he himself might his quietus make
With a bare bodkin? Who would these fardels bear,
To grunt and sweat under a weary life,
But that the dread of something after death-
The undiscover’d country, from whose bourn
No traveller returns- puzzles the will,
And makes us rather bear those ills we have
Than fly to others that we know not of?
Thus conscience does make cowards of us all,
And thus the native hue of resolution
Is sicklied o’er with the pale cast of thought,
And enterprises of great pith and moment
With this regard their currents turn awry
And lose the name of action.- Soft you now!
The fair Ophelia!- Nymph, in thy orisons
Be all my sins rememb’red.

Les Liaisons dangereuses 
by Pierre Choderlos de Laclos

Excerpt from Letter 115 (translated from French):

LETTER CXV.
The VISCOUNT DE VALMONT to the MARCHIONESS DE MERTEUIL.

It is a most unaccountable thing, my charming friend, when we are at a remote distance, we cannot so readily understand each other. Whilst I was near you, we always had the same sentiments, and viewed every object in the same light; because I am now about three months absent, we are no longer of the same opinion on any thing. Which of us is in the wrong? You certainly will not hesitate in your answer: but I, more wise, or more polite, will not decide. I shall only reply to your letter, and continue to lay my conduct open.
First, accept my thanks for the intelligence of the reports flying about me; that does not make me uneasy: I think soon I shall be furnished with materials to silence them all. Have a little patience; I shall again appear more celebrated than ever, and more worthy of you.
I expect even they will give me credit for the affair of the little Volanges, which you affect to treat as such a trifle: as if there was no merit in carrying in one night a young girl from a favoured lover; to make use of her after as much as one chooses, even as their own property, and without any farther trouble; to obtain from her what one dare not even require from girls whose vocation it is; and all this without in the least disturbing her tender affection; without making her inconstant, or even false; for certainly I don’t engage her imagination. So that after my fancy is at an end, I will deliver her into her lover’s arms, without, as I may say, her having taken notice of any thing. Pray is that so common an exploit? Yet believe, when she is gone from under my tuition, the principles I have instilled into her will nevertheless display themselves; and I prophesy, the timid scholar will take a flight that will do honour to her master.
If, however, they like heroics better, I will show my Presidente; this model cited for every virtue, respected even by our greatest libertines; insomuch, they had given up the idea of attacking her. I will show her, forgetting duty and virtue, sacrificing her reputation and two years prudence to run after the happiness of pleasing me; intoxicated with love; sufficiently recompensed for so many sacrifices by a word, a look, which yet she will not always obtain. I will do more, I will even abandon her; and if I know this woman, I shall not have a successor; she will resist the necessity of consolation; the habitude of pleasure; even the thirst for revenge: she shall have existed for me only; and let her career be long or short, I alone will have opened and shut the barrier; when once I rise to this triumph, I will tell my rivals, “that is my exploit, search the world for such an example.”