 Still, there is room for a distinction between epistêmê and technê. Several authors attribute to Zeno the notion that a technê is a systematic collection of cognitions (katalêpseis) unified by practice for some goal advantageous in life (SVF I 73). The difference between technê and epistêmê properly speaking is that the latter is said to be secure and unshakeable by reason (Stobaeus 2.73,16–74,3). In general, however, technê does not have the same kind of stability (Cicero, On Ends III.50). Indeed, such technai as love of music, and liberal arts in general, are not even called knowledge (Stobaeus, 2.67, 5–12; cf Seneca, Letters 88). Nevertheless, such distinctions between epistêmê and technê do not keep the Stoics from characterizing virtue as technê. This special technê does consist in a secure and unshakeable insight into what is appropriate at each juncture of life.