Aristotle, Poetics 1452e34-1453a9
“Since it is right that the structure of the best tragedy not be simple but be complex instead and evoking both fearful and pitiful emotions—for that is the particular power of this kind of artistic representation—as an initial principle, it is clear that decent men should not be be shown undergoing a change from good fortune to bad fortune, for that is repugnant rather than pitiful or fearful. And it is also not right for depraved people to enjoy a change from bad fortune to good fortune, because that is the least tragic notion of all and has none of the necessary qualities. Such a plot does not create empathy and fails to produce pity or fear.
[Tragedy] should also not show an especially bad person falling from good fortune to bad—for this might engender empathy but without pity or fear since the first is felt for someone who is unworthy of bad fortune and the second is for someone who is similar [to us] (pity is for someone unworthy of suffering; fear is for someone like us suffering). The response to [a wicked person] falling is not pitiful or fearful. What remains [for tragedy] is the person in between. A person like this is not impeccable in terms of justice nor for his wickedness and evil, but he falls into misfortune because of some kind of mistake. This kind of person is from those well-known families, like Oedipus or Thyestes.”
γον, ἐφεξῆς ἂν εἴη λεκτέον τοῖς νῦν εἰρημένοις. ἐπειδὴ οὖν δεῖ τὴν σύνθεσιν εἶναι τῆς καλλίστης τραγῳδίας μὴ ἁπλῆν ἀλλὰ πεπλεγμένην καὶ ταύτην φοβερῶν καὶ ἐλεεινῶν εἶναι μιμητικήν (τοῦτο γὰρ ἴδιον τῆς τοιαύτης μιμήσεώς ἐστιν), πρῶτον μὲν δῆλον ὅτι οὔτε τοὺς ἐπιεικεῖς ἄνδρας δεῖ μεταβάλλοντας φαίνεσθαι ἐξ εὐτυχίας εἰς δυστυχίαν, οὐ γὰρ φοβερὸν οὐδὲ ἐλεεινὸν τοῦτο ἀλλὰ μιαρόν ἐστιν· οὔτε τοὺς μοχθηροὺς ἐξ ἀτυχίας εἰς εὐτυχίαν, ἀτραγῳδότατον γὰρ τοῦτ’ ἐστὶ πάντων, οὐδὲν γὰρ ἔχει ὧν δεῖ, οὔτε γὰρ φιλάνθρωπον οὔτε ἐλεεινὸν οὔτε φοβερόν ἐστιν· οὐδ’ αὖ τὸν σφόδρα πονηρὸν συμβαῖνον. ὁ μεταξὺ ἄρα τούτων λοιπός. ἔστι δὲ τοιοῦτος ὁ μήτε ἀρετῇ διαφέρων καὶ δικαιοσύνῃ μήτε διὰ κακίαν καὶ μοχθηρίαν μεταβάλλων εἰς τὴν δυστυχίαν ἀλλὰ δι’ ἁμαρτίαν τινά, τῶν ἐν μεγάλῃ δόξῃ ὄντων καὶ εὐτυχίᾳ, οἷον Οἰδίπους καὶ Θυέστης καὶ οἱ ἐκ τῶν τοιούτων γενῶν ἐπιφανεῖς ἄνδρες.
This passage (and a few others) have been misread since the rise of Christianity to mean that the tragic protagonist “suffers a fall because of a tragic flaw”. This is essentially bogus for lexicographical and contextual reasons. In early Greek, hamartia means to make a mistake: it comes from an archery metaphor and is related to the verb hamartanô, which means “to miss the mark”. This is a mistake that is not connected to an essential character goodness or badness.
from Beekes 2010
The Christian use of hamartia is “sin”, which, as we all know from our Sunday School, is innate and a sign of our essential badness. Wanting to have sex with people is a sin; driving badly and hitting someone from inattention is an accident. In my understanding of tragedy, hamartia means the latter. Yes, one might be distractable and an essentially bad driver and we may see this as in some way a flaw, but this is a cultural perspective that mixes determinism and responsibility in a strange way.
Contextually, Aristotle makes the specific point that the tragic hero should not be essentially wicked. If one is essentially wicked, the audience cannot make the key identification necessary to feel pity or fear. Now, one could argue that in a Christian context where everyone is flawed because of sin, the doctrine might still be said to apply. But this is not the Aristotelian context and this is not what Aristotle had in mind.