The World's Greatest Books [Volumes 1-15, 17-20]

Reason instructs us that all our ideas must have some foundation of truth, for it could not be that the All-Perfect and the All-True should otherwise have put them into us; and because our reasonings are never so evident or so complete when we sleep as when we wake, although sometimes during sleep our imagination may be more vivid and positive, it also instructs us that such truth as our thoughts have will assuredly be in our waking thoughts rather than in our dreams.

V.--Why I Do Not Publish "The World"

I have always remained firm in my resolve to assume no other principle than that which I have used to demonstrate the existence of God and of the soul, and to receive nothing which did not seem to me clearer andmore certain than the demonstrations of the philosophers had seemed before; yet not only have I found means of satisfying myself with regard to the principal difficulties which are usually treated of in philosophy, but also I have remarked certain laws which God has so established in nature, and of which He has implanted such notions in our souls, that we cannot doubt that they are observed in all which happens in the world.

The principal truths which flow from these I have tried to unfold in a treatise ("On the World, or on Light"), which certain considerations prevent me from publishing. This I concluded three years ago, and had begun to revise it for the printer when I learned that certain persons to whom I defer had disapproved an opinion on physics published a short time before by a certain person [Galileo, condemned by the Roman Inquisition in 1633], in which opinion I had noticed nothing prejudicial to religion; and this made me fear that there might be some among my opinions in which I was mistaken.

I now believe that I ought to continue to write all the things which I judge of importance, but ought in no wise to consent to their publication during my life. For my experience of the objections which might be made forbids me to hope for any profit from them. I have tried both friends and enemies, yet it has seldom happened that they have offered any objection which I had not in some measure foreseen; so that I have never, I may say, found a critic who did not seem to be either less rigorous or less fair-minded than myself.

Whereupon I gladly take this opportunity to beg those who shall come after us never to believe that the things which they are told come from me unless I have divulged them myself; and I am in nowise astonished at the extravagances attributed to those old philosophers whose writings have not come down to us. They were the greatest minds of their time, but have been ill-reported.Why, I am sure that the most devoted of those who now follow Aristotle would esteem themselves happy if they had as much knowledge of nature as he had, even on the condition that they should never have more! They are like ivy, which never mounts higher than the trees which support it, and which even comes down again after it has attained their summit. So at least, it seems to me, do they who, not content with knowing all that is explained by their author, would find in him the solution also of many difficulties of which he says nothing, and of which, perhaps, he never thought.