a note on ad hominem consideration of a line of argument

ad hominem is sometimes lumped together with attacking the example someone chose to illustrate a point rather than their argument [or, if you insist, "the" argument.]

But consider Michael Martin on R. Taylor's case for teleology and design.  Martin's 1990 book reports that Taylor had occasion to respond to critics but that he did not reply (although someone sympathetic to his argument, Creel, did reply.)

When we are asked to consider such things as "I think that what Philo was trying to say ... " or "I think that what Philo may have intended was ..." then the failure to respond can be more than a refusal of dialog - especially so if the argument or line of thought has been published as a non-specialist text.

In Taylor's case, his book "Metaphysics" was not aimed just at the specialist, but also at a more general reader and likely had the philosophy student in mind.

That an effort to defend or clarify is seen to fail, is one thing. To fail to make that effort is quite another.  Whether due to arrogance, or unwillingness to retract, or due to pride or neglect, it is a moral failing of the philosopher.

Sometimes the philosopher's choice of where to speak can be likened to the choice of a regrettable example.   Peter Singer launched a storm of irrational and emotional protest by proposing to speak on medical ethics and the termination of life at Uni. Marburg/Lahn.  This location was construed as no idle choice for the organizers and no doubt Singer was ignorant of the history of the Marburg University medical clinic in the Nazi "T4" program (and the university's readiness to hire Nazi medical staff after the war.

To make matters worse, Marburg, untouched in the war, failed to rebuild the great synagogue destroyed in the November Pogrom.  Marburg and the surrounding area had failed to find even a small lane to bear the name of Hermann Cohen (other streets bear the names of academic notables - Cohen merited only a small plaque at the old university.)  For years the inscription at the old site was in memory of those residents of Marburg who feel in the war ( a slight variant on typical village memorials to Great War heros which one finds in small towns in the area.)

Once Marburg psychiatric housing had been emptied, it served to house slave labourers for the Noble dynamite factory at near-by Allendorf (per documentation at the archive of the University of Minnesota.)

Historians indicate that public objections to Action-T4 had an affect on the Nazi regime: there is no historical record that any public objections by Marburg notables were ever made such as might have served to spare the Jews of Marburg, the home of theology and philosophy and sometime home to the industrious Brothers Grimm.

When a philosopher from Marburg says nothing (Heidegger never returned to Marburg to urge the rebuilding of the synagogue - nor did the illustrious Hannah Arendt) it can be as serious a concern as when a philosopher choses to advocate mercy killing in a town which has yet to come to terms with its complicity in willful human slaughter.  It brings into question who is that "we" who are ready to engage Peter Singer in that particular dialog no matter how impressive his line of argument.  The city of Marburg is not yet that place.  Tourists arriving to see the St Elizabeth church and enjoy shopping in the quaint streets are able to enjoy their visit most often without having once to consider who is missing from the scene.  A building advertises the Grimm brothers worked here; no building says "the family Rosenberg had a business here prior to ..." or "This house was purchased below market price after the Rosenberg family ...".  They need not advertise: but the plaque needs to be there to be read by this generation and the next and perhaps even one more after.  And the synagogue must be rebuilt.  link: History page of the tiny renewed Jewish community of Marburg.