So here again it is evident that those who aim at success in military plans and surprises of towns must have studied geometry, if not thoroughly at least enough to have a notion of proportion and the principles of equations;
for this kind of knowledge indeed is necessary not only for the above purpose but for making changes in the plan of camps, so as to enable us either in changing the whole plan of the camp to keep up the same proportion between the different parts enclosed in it,
or at other times while adhering to the same plan to increase or diminish the space included in the camp proportionately to the number of fresh arrivals or departures.
About this matter I have entered into greater detail in my notes on tactics.
I do not think anyone can fairly maintain that I attach too many qualifications to the art of generalship, by thus urging those who aim at mastering it to study astronomy and geometry.
On the contrary I strongly disapprove of all such superfluous acquirements in a profession as serve but for ostentation and fine talk, but while also disinclined to insist on any studies beyond those that are of actual use, in the case of necessary knowledge I am most exacting and earnest.
It is indeed strange that those who wish to learn the arts of dancing and flute-playing should consent to study as a preliminary the theory of rhythm and music and even to acquire some gymnastic training, because it is thought that perfection in either cannot be attained without such aid,
while those who aspire to the command of armies regard it as a grievance if we demand of them a certain slight acquaintance with other sciences.
This would mean that those who practise illiberal arts show greater diligence and emulation than those whose aim is to excel in the most honourable and serious of all employments — a proposition to which no sensible man would give his assent.
But these remarks must suffice on this subject. . . .
Walbank Commentary