In person he was handsome and graceful, through all the stages of his life. But he was careless of dress; and so little attentive to the adjustment of his hair, that he usually had it done in great haste, by several barbers at a time. He would sometimes clip, and sometimes shave his beard; and during the operation would be either reading or writing. His countenance, either when he spoke or held his tongue, was so calm and serene, that a Gaul of the first rank declared amongst his friends that he was so much mollified by it, as to be restrained from throwing him down a precipice, in his passage over the Alps, upon being admitted to approach him, under the pretext of speaking with him. His eyes were clear and bright; and he was willing it should be thought that there was something of a divine vigour in them. He was likewise not a little pleased to see people, upon his looking steadfastly at them, lower their countenances, as if the sun shone in their eyes. But in his old age, he saw very imperfectly with his left eye. His teeth were thin set, small and rough, his hair a little curled, and inclining to a yellow colour. His eyebrows met; his ears were small, and he had an aquiline nose. His complexion was betwixt brown and fair; his stature but low; though Julius Marathus his freedman says he was five feet and nine inches in height. This however was so much concealed by the just proportion of his limbs, that it was only perceivable upon comparison with some taller person standing by him.
From early youth he devoted himself with great diligence and application to the study of eloquence, and the other liberal arts. In the war of Mutina, notwithstanding the weighty affairs in which he was engaged, he is said to have read, written, and declaimed every day. He never addressed the senate, people, or soldiery but in a premeditated speech, though he was not destitute of the talent of speaking extempore. And lest his memory should fail him, as well as to prevent the loss of time in getting his speeches by heart, he resolved to read them all. In his intercourse with individuals, and even with his wife Livia, upon a subject of importance, he had all he would say down in writing, lest, if he spoke extempore, he should say more or less than was proper. He delivered himself in a sweet and peculiar tone, in which he was diligently instructed by a master. But when he had a cold, he sometimes made use of a crier for the delivery of his speeches to the people.
In his literary qualifications, without at all rivalling the attainments of Cæsar, he was on a level with most Romans of distinction of his time; and it is said that both in speaking and writing his style was eminent for its perfect plainness and propriety. His speeches on any public occasion were composed beforehand, and recited from memory; nay, so careful was he not to commit himself by any inconsiderate expression, that even when discussing any important subject with his own wife, he wrote down what he had to say, and read it before her. Like his uncle, he was strongly tinged with superstition; he was very much afraid of thunder and lightning, and always carried about with him a sealskin, as a charm against its power; notwithstanding which, in any severe storm, he was accustomed to hide himself in a chamber in the centre of his house, to be as much out of the way of it as possible; add to which, he was a great observer of dreams, and of lucky and unlucky days.
He neither slighted his own dreams, nor those of other people relating to himself. At the battle of Philippi, though he had resolved not to stir out of his tent, on account of being indisposed, yet, upon the occasion of a dream which a friend of his had, he altered his resolution; and it was fortunate for him that he did so; for the camp was taken, and his couch, upon a supposition of his being in it, was pierced in several parts, and cut to pieces. He had many frivolous silly dreams during the spring; but in the other parts of the year, his dreams were less frequent and more significative. Upon his frequently visiting a temple in the Capitol, which he had dedicated to Thundering Jove, he dreamed that Jupiter Capitolinus complained that his worshippers were taken from him, and that upon this he replied he had only given him the Thunderer for his porter. He therefore immediately hung the ceiling of the temple round with little bells; because such commonly hung at the gates of great houses. Upon occasion of a dream too, he always, on a certain day of the year, begged an alms of the people, reaching out his hand to receive the dole with which they presented him.