XXXIII. The second authority, is that of Lactantius Firmianus, an illustrious person, and a venerable member of the church; this great man (Lib. III. Divin. Instit. Cap. iv. v. and vi.) treats largely of the scepticism of Archesilaus, of whom we have spoken before, and after combating and confronting this philosopher effectually on the subject of universal doubt, admits without reserve, that he would have been right, if he had limited his scepticism to matters of physics, because there is not, nor ever can be any science, which will teach mankind, the causes and reasons of natural things: _Quanto faceret sapientius, ac verius, si exceptione facta diceret causas, rationesque duntaxat rerum cælestium, seu naturalium, quia sunt abditæ, nec sciri posse, quia nullus doceat, nec quæri opportere, quia inveniri quærendo non possunt_. XXXIV. Some of the sceptics themselves prove our conclusion, for they say, that the things appertaining to physics are singular, and that from singular things you cannot derive a science. But this reason does not satisfy me. In the first place, notwithstanding physical things are for the most part singular, they in some instances may cease to be singular. Thus, although every real entity is singular, it may, contemplated metaphysically, depart from its singularity. In fact, the schoolmen together with St. Thomas say, that physics may depart or be separated from their singular, but not from their sensible nature; and that mathematical things, may depart or be separated from their singular and sensible, but not from their intelligible nature; also, that metaphysical ones, may depart or be separated from their singular, sensible, and intelligible. In the next place, the axiom that from singular things you can derive no science, should be understood with some grains of allowance; that is, of such singular things as are particularly necessary to the individual, and are accidental to the species; but from those which appertain or belong to the species, science may be deduced, even when they are connected with the individual. For example. If I know scientifically; that man according to the general received opinion respecting him, is risible, I also know scientifically that Peter is risible, for in the following syllogism; _every man is risible; Peter is a man; and therefore Peter is risible_, is implied the truth of the premises, and the consequence deducible from it is, that it is scientifically evident. Further, if ever a philosopher should arise, who should know with certainty, the specific nature of all material entities, and from that knowledge, should be able to demonstrate all their properties, and the respective operations appertaining to each species, and in virtue of this extraordinary penetration, should be capable of giving reasons _à priori_ for all the phenomena of nature, we should not be able to deny, that such a philosopher possessed physical