to comment upon it. I thought that this would be a good opportunity to publish something entitled New Essays on the Understanding and to gain a more favourable reception for my thoughts by putting them in such good company. I thought too that I might benefit from someone else’s labour, not only to lessen mine (since it is easier to follow the thread of a good author than to do everything by one’s own efforts), but also to add something to what he has produced for us, which is always easier than to start from the beginning. It is true that my opinions frequently differ from his, but far from denying the merit of this famous writer I testify in his favour by showing where and why I differ from him, when I find that on certain significant points I have to prevent his authority from prevailing over reason.
Indeed, although the author of the Essay says hundreds of fine things which I applaud, our systems are very different. His is closer to Aristotle and mine to Plato, although each of us parts company at many points from the teachings of both of these ancient writers. He is more popular whereas I am sometimes forced to be a little more esoteric and abstract – which is no advantage for me, particularly when writing in a living language. However, I think that by using two speakers, one of whom presents opinions drawn from that author’s Essay and the other adds my comments, the confrontation will be more to the reader’s taste than a dry commentary from which he would have to be continually turning back to the author’s book in order to understand mine. Nevertheless it would be well to compare our writings from time to time, and to judge of his opinions only from his own book even though I have usually retained its wording. I am afraid that the obligation to follow the thread, when commenting on someone else’s treatise, has shut out any hope of my attaining to the charms of which dialogue is capable; but I hope that the matter will make up for the shortcomings of the manner.
Our disagreements concern points of some importance. There is the question whether the soul in itself is completely blank like a writing tablet on which nothing has as yet been written – a tabula rasa – as Aristotle and the author of the Essay maintain, and whether everything which is inscribed there comes solely from the senses and experience; or whether the soul inherently contains the sources of various notions and doctrines, which external objects merely rouse up on suitable occasions, as I believe and as do Plato … and all those who understand in this sense the passage in St Paul where he says that God’s law is written in our hearts (Romans, 2: 15). The Stoics call these sources ‘Prolepses’, that is fundamental assumptions or things taken for granted in advance. Mathematicians call them common notions or koinai ennoiai. Modern philosophers give them other fine names … ‘seeds of eternity’ and also zopyra – meaning living fires or flashes of light hidden inside us but made visible by the stimulation of the senses, as sparks can be struck from a steel. And we have reason to believe that these flashes reveal something divine and eternal: this appears especially in the case of necessary truths. That raises another question, namely whether all truths depend on experience, that is on induction and instances, or if some of them have some other foundation. For if some events can be foreseen before any test has been made of them, it is obvious that we contribute something from our side. Although the senses are necessary for all our actual knowledge, they are not sufficient to provide it all, since they never give us anything but instances, that is particular or singular truths. But however many instances confirm a general truth, they do not suffice to establish its universal necessity; for it does not follow that what has happened will always happen in the same way. For instance, the Greeks and Romans and all the other nations on earth always found that within the passage of twenty-four hours day turns into night and night into day. But they would have been mistaken if they had believed that the same rule holds everywhere, since the contrary was observed during a stay in Novaya Zemlya. And anyone who believed that it is a necessary and eternal truth at least in our latitudes would also be mistaken, since we must recognize that neither the earth nor even the sun exist necessarily, and that there may come a time when this beautiful star no longer exists, at least in its present form, nor its whole system.
From this it appears that necessary truths, such as we find in pure mathematics and particularly in arithmetic and geometry, must have principles whose proof does not depend on instances nor, consequently, on the testimony of the senses, even though without the senses it would never occur to us to think of them. This distinction must be thoroughly observed, and Euclid understood that so well that he demonstrates by reason things that experience and sense-images make very evident. Logic also abounds in such truths, and so do metaphysics and ethics, together with their respective products, natural theology and natural jurisprudence; and so the proof of them can only come from inner principles, which are described as innate.
It would indeed be wrong to think that we can easily read these eternal laws of reason in the soul, as the Praetor’s edict can be read on his notice-board, without effort or inquiry; but it is enough that they can be discovered within us by dint of attention: the senses provide the occasion, and successful experiments also serve to corroborate reason, somewhat as checks in arithmetic help us to avoid errors of calculation in long chains of reasoning.
It is in this same respect that man’s knowledge differs from that of beasts: beasts are sheer empirics and are guided entirely by instances. While men are capable of demonstrative knowledge, beasts, so far as one can judge, never manage to form necessary propositions, since the faculty by which they make sequences is something lower than the reason which is to be found in men. The sequences of beasts are just like those of simple empirics who maintain that what has happened once will happen again in a case which is similar in the respects that they are impressed by, although that does not enable them to judge whether the same reasons are at work. That is what makes it so easy for men to ensnare beasts, and so easy for simple empirics to make mistakes. Even people made cunning by age and experience are not proof against this when they trust too much to their past experience; as has happened to various people engaged in civil or military affairs, through their not taking sufficiently to heart that the world changes and that men become cleverer and find hundreds of new tricks – whereas the deer and hares of our time are not becoming craftier than those of long ago. The sequences of beasts are only a shadow of reasoning, that is, they are nothing but a connection in the imagination – a passage from one image to another; for when a new situation appears similar to its predecessor, it is expected to have the same concomitant features as before, as though things were linked in reality just because their images are linked in the memory. It is true, moreover, that reason counsels us to expect ordinarily that what we find in the future will conform to long experience of the past; but even so, this is no necessary and infallible truth, and it can fail us when we least expect it to, if there is a change in the reasons which have been maintaining it. This is why the wisest men do not trust it so implicitly that they neglect to probe somewhat, where possible, into the reason for such regularities, in order to know when they will have to allow exceptions. For only reason is capable of establishing reliable rules, of making up the deficiencies of those which have proved unreliable by allowing exceptions to them, and lastly of finding unbreakable links in the cogency of necessary inferences. This last often provides a way of foreseeing events without having to experience sensible links between images, as beasts must. Thus what shows the existence of inner sources of necessary truths is also what distinguishes man from beast.
Perhaps our gifted author will not entirely disagree with my view. For after devoting the whole of his first book to rejecting innate illumination, understood in a certain sense, he nevertheless admits at the start of his second book, and from there on, that ideas which do not originate in sensation come from reflection. But reflection is nothing but attention to what is within us, and the senses do not give us what we carry with us already. In view of this, can it be denied that there is a great deal that is innate in our minds, since we are innate to ourselves, so to speak, and since we include Being, Unity, Substance, Duration, Change, Action, Perception, Pleasure, and hosts of other objects of our intellectual ideas? And since these objects are immediately related to our understanding and always present to it (although our distractions and needs prevent us being always aware of them), is it any wonder that we say that these ideas, along with what depends on them are innate in us? I have also used the analogy of a veined block of marble, as opposed to an entirely homogeneous block of marble, or to a blank tablet – what the philosophers
