Behind any inferential argument lays a structure of conjunctive statements or a network of equally admitted elements: there are premises, conclusions, and the argument itself.
The admission of such elements occurs only in respect of their existence. The inferential structure is ignored.
One who pays attention only to such conjunctive structure can be accused of being a bad interlocutor or even a bad user of reasoning. But the original fault belongs to arguments themselves.
Ad hominem arguments are also born from the same conjunctive structure of honest and valid arguments. From the sheer admission of the existence of the argument and of its elements, it is easy to come to its author, who has a stronger existence than his arguments.
Therefore, to some extent and in the practice of argumentation, the ad hominem arguments seem to be fair attacks to the valid arguments, as if they would be concerned with its inferential structure.
At the same time, the author of valid arguments should pay attention to their conjunctive structure. Their force of persuasion is greater when they approach subject matters which are closer to the existence of their author.