Lac habet, ergo peperit: History of an Example

In this paper we trace the history of the example of tekmerion or first-figure sign syllogism contained in Aristotle’s Prior Analytics (II, 27) : the fact that a woman has milk in the breast is the sign that she has given birth. This example, either in its original Aristotelian version or in some remodeling of it, is found in virtually every logical department of Western Aristotelism, from late antiquity to the thirteenth century, and its occurrence is functional to the illustration of distinct, and sometimes conflicting, logical doctrines.