Montaigne

Michel Eyquem, Lord of Montaigne (1533-1592)
(1) Michel de Montaigne. 1991 The Complete Essays. London: Penguin Books P. 755
The Complete Essays (1571-1592)
To the Reader
'Do what thou hast to do, and known thyself' - that great precept is often cited by Plato; (2), each clause of it embraces our entire duty, generally, and similarly embraces its fellow. Whoever would do what he has to do would see that the first thing he must learn is to know what he is and what is properly his. And whoever does know himself never consider external things to be his; about all other things he loves and cultivates himself: he rejects excessive concerns as well as useless thoughts and resolutions. [Folly never thinks it has enough, evem when it obtains what it desires, but W]isdom is happy with is to hand and is never vexed with itself] (3)
Michel de Montaigne. Essais. Book I, Chapter III " Our emotions get carried away beyond us"
(2) Plato. Timaeus, 72a. Cf. Erasmus, Adages , Nosce teipsum (I,VII,XCV)
(3) Cicero Tusc, disput,. V, xviii
We should have wives, children, property and above all, good health ......if we can : but we should not become so attached to them that our hapiness depends on them. We shoul set aside a room, put ourselves, at the back of the shop, keeping it entirely free and establishing there our true liberty, our principal solitude and asylum. Within it our normal conversation should be of ourselves, with ourselves, so privy that no commerce or communication with the outside world should find a place there
Michel de Montaigne, Ensayos. Libro I. Capítulo XXXIX "De la soledad"
Things in respect to themselves have, per adventure, their weight, measures, and conditions; but when we once take them into us, the soul forms them as she pleases. Death is terrible to Cicero, coveted by Cato, indifferent to Socrates. Health, conscience, authority, knowledge, riches, beauty, and their contraries, all strip themselves at their entering into us, and receive a new robe, and of another fashion, from the soul; and of what colour, brown, bright, green, dark, and of what quality, sharp, sweet, deep, or superficial, as best pleases each of them, for they are not agreed upon any common standard of forms, rules, or proceedings; every one is a queen in her own dominions. Let us, therefore, no more excuse ourselves upon the external qualities of things; it belongs to us to give ourselves an account of them. Our good or ill has no other dependence but on ourselves. 'Tis there that our offerings and our vows are due, and not to fortune she has no power over our manners; on the contrary, they draw and make her follow in their train, and cast her in their own mould.
Michel de Montaigne, Ensayos. Book I. Chapter 50 "On Democritus and Heraclitus"