It is absurd to hold that a man ought to be ashamed of being unable to defend himself with his limbs but not of being unable to defend himself with reason when the use of reason is more distinctive of a human being than the use of his limbs.

[πρὸς δὲ τούτοις ἄτοπον εἰ τῷ σώματι μὲν αἰσχρὸν μὴ δύνασθαι βοηθεῖν ἑαυτῷ, λόγῳ δ᾽ οὐκ αἰσχρόν: ὃ μᾶλλον ἴδιόν ἐστιν ἀνθρώπου τῆς τοῦ σώματος χρείας.]

Aristotle (384-322 BC) Greek philosopher
Rhetoric [Ῥητορική; Ars Rhetorica], Book 1, ch. 1, sec. 12 (1.1.12) / 1355b.1 (350 BC) [tr. Roberts (1924)]
    (Source)

(Source (Greek)). Alternate translations:

Absurd were it, if inability to defend oneself, in the case of the body be disgraceful, but in the case of the reason, which is more peculiarly the characteristic of man than the use of his body, be not disgraceful.
[Source (1847)]

It were absurd, if, while it is disgraceful for a man not to be able to assist himself by his person, it were not disgraceful to be unable to do this by his speech, which is more a peculiarity of man than the exercise of the body.
[tr. Buckley (1850)]

It would be absurd that, while incapacity for physical self-defence is a reproach, incapacity for mental defence should be none; mental effort being more distinctive of man than bodily effort.
[tr. Jebb (1873)]

It would be absurd if it were considered disgraceful not to be able to defend oneself with the help of the body, but not disgraceful as far as speech is concerned, whose use is more characteristic of man than that of the body.
[tr. Freese (1926)]

It would make no sense for an inability to defend oneself by physical means to be a source of shame, while an inability to defend oneself by verbal means was not, since the use of words is more specifically human than the use of the body.
[tr. Waterfield (2018)]

It is strange if it is a shameful thing not to be able to come to one's own aid with one's body but not a shameful thing to be unable to do so by means of argument, which is to a greater degree a human being's own than is the use of the body.
[tr. Bartlett (2019)]