Vitae philosophorum

21. He who understands the limits of life knows how easy it is to procure enough to remove the pain of want and make the whole of life complete and perfect. Hence he has no longer any need of things which are not to be won save by labour and conflict.

22. We must take into account as the end all that really exists and all clear evidence of sense to which we refer our opinions; for otherwise everything will be full of uncertainty and confusion.

23. If you fight against all your sensations, you will have no standard to which to refer, and thus no means of judging even those judgements which you pronounce false.