Vitae philosophorum
Diogenes Laertius
Diogenes Laertius. Hicks, R. D., editor. Cambridge, MA.: Harvard University Press; London: William Heinemann Ltd., 1925.
9. If all pleasure had been capable of accumulation,—if this had gone on not only by recurrence in time, but all over the frame or, at any rate, over the principal parts of man’s nature, there would never have been any difference between one pleasure and another, as in fact there is.
10. If the objects which are productive of pleasures to profligate persons really freed them from fears of the mind,—the fears, I mean, inspired by celestial and atmospheric phenomena, the fear of death, the fear of pain; if, further, they taught them to limit their desires, we should never have any fault to find with such persons, for they would then be filled with pleasures to overflowing on all sides and would be exempt from all pain, whether of body or mind, that is, from all evil.
11. If we had never been molested by alarms at celestial and atmospheric phenomena, nor by the misgiving that death somehow affects us, nor by neglect of the proper limits of pains and desires, we should have had no need to study natural science.