Shouldn’t logos give us insight? After all, even with “ye shall know them by their fruits,” we can say speech is a deed of sorts. And why “talking much?” Can’t a few words alone deceive?
The emphasis needs to be on “talking much about oneself.” The deception may involve others, but they have to care enough to listen and then peel back the layers built up. So we’re either talking about 1) writers or others who can command an audience or 2) one deceiving oneself. One can pile speech upon oneself and block self-knowledge. How does one speak, act, or think in order to establish proper self-reflection? Does it occur alone, or with others a certain way? An author seeking to convey something very particular has to assume specific things about what others know and don’t know. Those assumptions lead back to what they know and don’t know about him.