The Lives and Opinions of Eminent Philosophers by Diogenes Laërtius (best free ebook reader txt) 📕

xml:lang="grc">δόξα) also supposition (ὑπόληψις). And say that it is at times true, and at times false; for that, if it is supported by testimony, and not contradicted by testimony, then it is true; but if it is not supported by testimony, and is contradicted by testimony, then it is false. On which account they have introduced the expression of “waiting,” as if, before pronouncing that a thing seen is a tower, we must wait till we come near, and learn what it looks like when we are near it.

They say that there are two passions⁠—pleasure and pain⁠—which affect everything alive. And that the one is natural, and the other foreign to our nature; with reference to which all objects of choice and avoidance are judged of. They say also that there are two kinds of investigation: the one about facts, the other about mere words. And this is as far as an elementary sketch can go⁠—their doctrine about division, and about the criterion.

Let us now go to the letter:

Epicurus to Herodotus, Wishing He May Do Well

For those, O Herodotus, who are not able accurately to comprehend all the things which I have written about nature, nor to investigate those larger books which I have composed on the subject, I have made an abridgment of the whole discussion on this question, as far as I thought sufficient to enable them to recollect accurately the most fundamental points; that so, on all grave occasions, they might be able to assist themselves on the most important and undeniable principles; in proportion as they devoted themselves to speculations on natural philosophy. And here it is necessary for those who have made sufficient progress in their view of the general question, to recollect the principles laid down as elements of the whole discussion; for we have still greater need of a correct notion of the whole than we have even of an accurate understanding of the details. We must, therefore, give preference to the former knowledge, and lay up in our memory those principles on which we may rest, in order to arrive at an exact perception of things, and at a certain knowledge of particular objects.

Now one has arrived at that point when one has thoroughly embraced the conceptions, and, if I may so express myself, the most essential forms, and when one has impressed them adequately on one’s senses. For this clear and precise knowledge of the whole, taken together, necessarily facilitates one’s particular perceptions, when one has brought one’s ideas back to the elements and simple terms. In short, a veritable synthesis, comprising the entire circle of the phenomena of the universe, ought to be able to resume in itself, and in a few words, all the particular facts which have been previously studied. This method being useful even to those who are already familiarised with the laws of the universe, I recommend them, while still pursuing without intermission the study of nature, which contributes more than anything else to the tranquillity and happiness of life, to make a concise statement or summary of their opinions.

First of all then, Herodotus, one must determine with exactness the notion comprehended under each separate word, in order to be able to refer to it, as to a certain criterion, the conceptions which emanate from ourselves, the ulterior researches and the difficulties; otherwise the judgment has no foundation. One goes on from demonstration to demonstration ad infinitum; or else one gains nothing beyond mere words. In fact, it is absolutely necessary that in every word we should perceive directly, and without the assistance of any demonstration, the fundamental notion which it expresses, if we wish to have any foundation to which we may refer our researches, our difficulties, and our personal judgments, whatever in other respects may be the criterion which we adopt, whether we take as our standard the impressions produced on our senses, or the actual impression in general; or whether we cling to the idea by itself, or to any other criterion.

We must also note carefully the impressions which we receive in the presence of objects, in order to bring ourselves back to that point in the circumstances in which it is necessary to suspend the judgment, or even when the question is about things, the evidence of which is not immediately perceived.

When these foundations are once laid we may pass to the study of those things, the evidence of which is not immediate. And, first of all, we must admit that nothing can come of that which does not exist; for, were the fact otherwise, then everything would be produced from everything, and there would be no need of any seed. And if that which disappeared were so absolutely destroyed as to become nonexistent, then everything would soon perish, as the things with which they would be dissolved would have no existence. But, in truth, the universal whole always was such as it now is, and always will be such. For there is nothing into which it can change; for there is nothing beyond this universal whole which can penetrate into it, and produce any change in it.

And Epicurus establishes the same principles at the beginning of the great Abridgment; and in the first book of his treatise on Nature.140

Now the universal whole is a body; for our senses bear us witness in every case that bodies have a real existence; and the evidence of the senses, as I have said before, ought to be the rule of our reasonings about everything which is not directly perceived. Otherwise, if that which we call the vacuum, or space, or intangible nature, had not a real existence, there would be nothing on which the bodies could be contained, or across which they could move, as we see that they really do move. Let us add to this reflection that one cannot conceive, either in virtue of perception, or of any analogy founded on