Institutio Oratoria

For just as all kinds of produce are not provided by every country, and as you will not succeed in finding a particular bird or beast, if you are ignorant of the localities where it has its usual haunts or birthplace, as even the various kinds of fish flourish in different surroundings, some preferring a smooth and others a rocky bottom, and are found on different shores and in divers regions (you will for instance never catch a sturgeon or wrasse in Italian waters), so not every kind of argument can be derived from every circumstance, and consequently our search requires discrimination.

Otherwise we shall fall into serious error, and after wasting our labour through lack of method we shall fail to discover the argument which we desire, unless assisted by some happy chance. But if we know the circumstances which give rise to each kind of argument, we shall easily see, when we come to a particular

place,