Wisdom from the Early Stoics, Zeno of Citium 52

Such, then, is the logic of the Stoics, by which they seek to establish their point that the wise man is the true dialectician. 

For all things, they say, are discerned by means of logical study, including whatever falls within the province of Physics, and again whatever belongs to that of Ethics. 

For else, say they, as regards statement and reasoning Physics and Ethics could not tell how to express themselves, or again concerning the proper use of terms, how the laws have defined various actions. 

Moreover, of the two kinds of common-sense inquiry included under Virtue one considers the nature of each particular thing, the other asks what it is called. Thus much for their logic. 

—Diogenes Laërtius, 7.83 

IMAGE: Gilles Rousselet, Dialectic (c. 1635)