The reason which leads me to present you to this work is so excellent, and when you will know the design, I am afraid that you will have a good deal to take it for your protection, that I think I cannot do it better, to render it to you in some highly recommendable manner, that by telling you in a few words what I have proposed to do. I have always affirmed that these two questions, of God and of the soul, were the principal ones of those which must be demonstrated by the way of philosophy rather than of theology; for although it is incumbent upon us, to us who are faithful, to believe by faith that there is a God, and that the human soul does not die with the body, it certainly cannot be possible to be able to persuade to the infidels of any religion, even if it does not have any moral virtue, if, firstly, these two things are not proved to them by natural reason. And as far as it is often proposed in this life greater rewards for vice than for virtues, few persons would prefer the right to the useful, if they were not retained by the fear of God or the expectation of another life. And, since it is absolutely true that it is necessary to believe that there is a God, because he has learned us this way in the Holy Scriptures, and on the other hand that one must believe the Holy Writings, because they come from God; and that, because the faith is coming from God, who gives grace to make believe other things, can likewise make us to believe that He exists: we should not, however, propose that to the infidels, who could imagine that we would commit the fault which logicians call a circle.
And. really, I took care that you, gentlemen, with all the Theologians, did not faint only to deny that the existence of God can be proved by natural means, but also that inference is made from Holy Scripture, that His knowledge is much more clear than that that there are many things created, and indeed it is easy, that those who do not have it at all are guilty. As it appears by these words of Sagelle, chapter 13, where it is said that ignorance does not seem excusable; for their spirit has penetrated into the knowledge of the things of the world, and is it possible that they have not made it more easy to find out Lord thereof? And to the Romans, chapter one, it is said that they are inexcusable, and still, in the same place, by these words: That which may be known of God is manifest in them, it seems that we are advertised, that all that can be known of God may be shown by reason, that it is not necessary to seek elsewhere than in ourselves, and that our minds are able to furnish us. That is why, I thought, it would not be irrelevant that I come to see here by what means it can done, and what way to follow, to arrive at the knowledge of God with the greatest ease and certainty that we do not know the things of this world.
And with regard to the soul, how many have admitted that it is not necessary to know the nature of it, that some have even said that the human reason tell us that he died same time with his body, and that it is only the belief who learns the opposite to us, nonetheless, in as much as the Lateran Council, held under Leo X, in the eighth session, condemned them, and that he ordered expressly the Christian philophophes to answer to their arguments, and to employ all the forces of their minds to make the truth known, I also dared to undertake it in this work. First of all, knowing that the main reason, that makes many impious people to not believe that there is a God, and that the human soul is different from the body, and that they say that no one till now could demonstrate these two things; even if I am not at their opinion, but on the contrary I believe that almost all the reasons which have been given by so many, touching these two elements, make so many demonstrations when they are well understood, and it is almost impossible to introduce any new ones: it is the belief that cannot know do nothing more useful in Philofophy, than to search carefully for it once for the best and most solid, and to diffuse them in a clear and precise order, that it will henceforth be evident to everybody that they perform real demonstrations. And lastly, especially as many persons have desired it from me, of which they were aware I have a certain method of resolving all difficulties in the sciences; a method which is not new, having nothing more ancient than the truth, but from which they were aware that I used successfully in other encounters; I thought it was my duty to try something on this subject.
I have worked how best I could to explain in this Treaty all that can be said. I have drawn here all the different reasons that could be alleged to be used as evidence for our purpose; for I have never believed that this was necessary, except when there is no one to be sure; but I have treated the firsts and principals of such a way that I dared to propose them as very evident and very certain demonstrations. And I will say, moreover, that they do such that I do not think that there is any way in which the human mind can think of discovering better ones; for the importance of matter, and the glory of God to which all things are report, compel me to speak here a little more freely of myself than is my habit. Nevertheless, some certainty and evidences that I find in my reasons, I can not perceive myself that everyone is able to hear them. But, just as in geometry, there are many who have lightened us by Archimedes, by Apollonius, by Pappus, and by several others, who are pereived by all over as perfectly certain and evident, because they contain nothing which, considered separately, not being very easy to understand, and that there is no place where the consequences do not rank, and do not agree well with the antecedents; nevertheless, because they are a little long, and because they require a whole mind, they are taken and understood only by a very small number of people: even though they are the same as those of whom I am here, they are equal, even more, in certainty and evidence of demonstrations of geometrics, but they seem to me that they can not easily be heard by many, because they are too long and dependent on the lives of others, mainly because they ask for a completely free mind of all prejudge and who deserves to detach easily from the matters of the senses. And, really, there are not so many in the world that are fit for metaphysical speculations as for those of geometry. And, moreover, there is still this difference that, in geometry, since each one being persuaded of the opinion that there is left nothing which has not certain demonstration, those which do not check it entirely, are more likely than they will approve what is false, to make believe that they understand it, than to refute the true ones. It is not the same in philosophy, where, each believing that all his propositions are problematic, few performs add themselves to the search for truth; and even when they wish to acquire the reputation of strong minds, they do not study each other except to brazenly fight arrogantly against the most important ones.
It is why, gentlemen, whatever force may be expected by my reasons, because they belong to philosophy, I do not wish them to make a great effort on the minds, if you do not take them for your protection. Everybody thinks of your company being so great, and the name of the Sorbonne of such authority, that not only in regard to the faith, after the Sacred Councils, never has such deference been paid to the judgment of anybody, but with regard to the human philosophy, each believing that it is not possible to find elsewhere more solidity and perspicacity, nor more prudence and integrity in judgement: I do not doubt it, if you dare to take so much care from this work, as to try first to correct it; for, having knowledge of not only my infirmity, but also of my ignorance, I will not dare to state that it is free from errors; then, after adding to them the things that are lacking, make perfect those which are not perfect, and take the trouble yourself to give a fuller explanation to those who need it, or at least to warn me about it so that I can work on it, and, finally, after the reasons by which I know that there is a God, and that the human soul differs from the body, it will have been brought to the point of clarity and confidence, where it is clear that they may be led to the point where they will consider to be held for perfectly exact demonstrations, I want to declare this myself, and to testify to it publicly: I do not doubt, I say, that, if it does, all the erroneous and foolish opinions which have ever touched these two, will soon be effaced from the minds of men. For the truth will cause all the men and women of mind to believe in your judgment; and the authority, that the atheists, who are more arrogant than learned and wise, will strip them of their spirit of contradiction, or perhaps they themselves will create the ways which they will receive from them all persons of mind for demonstrations, lest they appear not understanding their intelligence; and, finally, all the others will be able to hear witness from so many testimonies, and there will no longer be anyone who can doubt the existence of God, and the true and real difference of the human soul with the body.
It is now up to you to judge of the fruit which would be the fruit of this claim, if it were once well established, which will see the losses which doubt has produced; but it would not be a good grace to say more in consideration of the cause of God and of religion to those who have always been the most worthy supports of the Catholic Church.