According to Plutarch, Cicero learned to distrust Caesar early, but occasionally questioned Caesar’s willingness or ability to destroy the Roman constitution; yet, though Caesar did not live to reap its fruits, he did lay a solid foundation for autocracy in Rome.
Plutarch, Life of Caesar Cap. IV (Full text on the Scaife Viewer):
“Cicero seemed to be the first to see beneath Caesar’s exterior and to have feared his mode of government (as though fearing the pleasant laughter of the sea), and when he first learned about the horror that lay hidden beneath this apparently benevolent and pleasant man, he said that he could see tyrannical intentions lurking in all of this man’s political projects. ‘But,’ he said, ‘when I see his hair so carefully adjusted, and when I see him scratching it with one finger, I can’t believe that he is capable of forming such a wicked plan as the destruction of our republic.’”
ὁ γοῦν πρῶτος ὑπιδέσθαι δοκῶν αὐτοῦ καὶ φοβηθῆναι τῆς πολιτείας ὥσπερ θαλάττης τὰ διαγελῶντα καὶ τὴν ἐν τῷ φιλανθρώπῳ καὶ ἱλαρῷ κεκρυμμένην δεινότητα τοῦ ἤθους καταμαθὼν Κικέρων ἔλεγε τοῖς ἄλλοις ἅπασιν ἐπιβουλεύμασιν αὐτοῦ καὶ πολιτεύμασι τυραννικὴν ἐνορᾶν διάνοιαν· „ἀλλ’ ὅταν” ἔφη „τὴν κόμην οὕτω διακειμένην περιττῶς ἴδω, κἀκεῖνον ἑνὶ δακτύλῳ κνώμενον, οὔ μοι δοκεῖ πάλιν οὗτος ἅνθρωπος εἰς νοῦν ἂν ἐμβαλέσθαι τηλικοῦτον κακόν, ἀναίρεσιν τῆς ῾Ρωμαίων πολιτείας.” ταῦτα μὲν οὖν ὕστερον.