To his deficiencies in the habit of diligent and accurate investigation are added others which singularly disqualify him for the task of a faithful historian. He was a reader of books rather than a student of men and things; he took upon trust what other people told him, instead of acquiring knowledge in a practical manner. He was ill-acquainted with the history of foreign countries. He was not, like Cæsar, a soldier; and therefore his descriptions of military affairs are often vague and indistinct, for he did not understand the tactics which he professed to describe. He was not, like Thucydides, a politician or a philosopher; and hence the little trustworthy information which we derive from him on questions connected with constitutional changes. He did not fit himself, like Herodotus, by travelling; and thus he is often ignorant of the localities which he describes, even though they are within the limits of Italy. Hence the difficulties in the way of understanding the route of Hannibal and his army across the Alps, the battle of Thrasimene, and the defeat at the Caudine Forks. He was not a philosopher, a lawyer, or a politician: he could embrace with the eye and depict with the hand of an artist everything which was external and tangible; but he could not penetrate the secret motives which actuate the human will, nor form a clear conception of the fundamental, legal and political principles which animated the institutions, and gave rise to the peculiarities, of Roman constitutional history.