When the præses is the author he is usually called author, defendant, or proponent, never respondent, but the opposing respondent is sometimes a participating author.
The following case is one of our difficulties, and shows the necessity of looking further than the title:—
"Dissertatio de Hæmorrhoidibus, præses Geo. Francus, respondens J. G. Carisius, Heidelb. 1672."
The dedication to this is signed by Francus, with this remark, "Dissertationem Medicam primitias nempe meas offerre debui," proving him to be the author.
And in numerous cases where the names of a præses and respondent occur on the title without the word author being attached to either, the preface or dedication is signed sometimes by one and sometimes by the other, and the authorship must be attributed accordingly.
But with regard to those Disputations in which only the names of præses and respondent occur on the title, we must recollect that the antithesis is not always between them, but between the opponents, whether mentioned or not, and the author who responds to their strictures, the præses being only the arbiter between them.
The principal cause of our troubles in these matters is not, however, to be found so much in the separate dissertations in their original publication, as in the collected editions of them by Haller and others. In these collections the name of the præses is constantly given as author of the thesis in the heading lines of the text, even when the title, in agreement with its original publication, attaches the word auctor to the name of the defendant or respondent; are we in these cases to suppose that these heading lines have really been left to the caprice of the printer, who has adopted the name of the præses as occurring first on the title, on the principle of first come first served?
In Haller's Collection of Disputationes Chirurgicæ contrarieties constantly occur, the exact sameness of construction in the titles being followed sometimes by the name of the præses and sometimes by that of the defendant, on the heading lines of the text; as, for instance, in one where, though the fly-title mentions Orth as the "respondens auctor," the dissertation is in the heading placed under the name of Salzmann, the præses.
Other instances of this difficulty occur in Gruner's Delectus Dissertationum Medicarum Jenensium, in which a large number are attributed to the præses Baldinger, in a title-construction which mentions the names of the proponents as authors. In Haller's Disputationes ad Morborum historiam, the regular titles are omitted, and the two names, sometimes præses and respondent, sometimes respondent and opponent, or defendant and respondent, are given coupled by an et as the authors of the dissertation, the first name, however, gaining the honour of the heading line. I give one or two instances exhibiting the confusion involved in the question.