Dissertation on a Solid Body Naturally Contained Within a Solid

DISSERTATIONIS PRODROMVS.

both in regard to the place where it is found and the place in which it was produced. Yet, no one who is ignorant of the mode of production will easily determine the place of production, and every dissertation regarding the mode of production is vain unless we have a certain knowledge regarding the nature of the matter. From this, it is evident how many questions must be resolved for a single question to be satisfied.

The second cause, which is the nurse of doubts, seems to me to be this: that in the examination of natural things, those things which cannot be determined with certainty are not distinguished from those which can be determined with certainty. Hence it happens that the primary schools of Phylosophorum philosophers are reduced to two classes. For some consider it a matter of religious duty to withhold belief even from demonstrations themselves, fearing that the same error which they have frequently detected in other assertions might lie within them. Others, on the contrary, would in no way allow themselves to be restricted to holding as certain only those things to which no person of sound mind and sound senses could deny belief, thinking that everything which appeared to them beautiful and ingenious must be true. Indeed, even the patrons of experience themselves have rarely maintained such moderation, as they would either reject even the most certain principles of Natura Nature, or consider principles they themselves had invented as demonstrated. Therefore, in order to avoid this reef—a point which Seneca frequently inculcates regarding the precepts of morals—I have judged it necessary to urge this most strongly in Physicis physics; he says that those moral precepts are best which are common.