Aristotle
Greek philosopher and a scientist.
A whole is that which has beginning, middle, and end.
We should venture on the study of every kind of animal without distaste; for each and all will reveal to us something natural and something beautiful.
Aristotle sees no difference between the falling of a leaf or a stone and the death of the good and noble people in the ship; nor does he distinguish between the destruction of a multitude of ants by an ox depositing on them his excrement and the death of worshippers killed by the fall of the house when its foundations give way. In short, the opinion of Aristotle is this: Everything is the result of management which is constant, which does not come to an end and does not change any of its properties, as e.g., the heavenly beings, and everything which continues according to a certain rule... But that which is not constant, and does not follow a certain rule... is due to chance and not to management; it is in no relation to Divine Providence. Aristotle holds that it is even impossible to ascribe to Providence that management of these things. ...It is the belief of those who turned away from our Law and said: "God hath forsaken the earth." (Ezek. ix. 9)
For the purposes of poetry a convincing impossibility is preferable to an unconvincing possibility.
Even when laws have been written down, they ought not always to remain unaltered.
Nature does nothing uselessly.
Law is order, and good law is good order.
Piety requires us to honor truth above our friends.
It is the mark of an educated man to look for precision in each class of things just so far as the nature of the subject admits; it is evidently equally foolish to accept probable reasoning from a mathematician and to demand from a rhetorician scientific proofs.
Remark: While this quote is known as Aristotle's, he didn't proposed as his own saying, but as a citation from the other author. The full text is: But 'change in all things is sweet', as the poet says, because of some vice.
When people are friends, they have no need of justice, but when they are just, they need friendship in addition.
He who has overcome his fears will truly be free.
The young have exalted notions, because they have not been humbled by life or learned its necessary limitations; moreover, their hopeful disposition makes them think themselves equal to great things—and that means having exalted notions. They would always rather do noble deeds than useful ones: Their lives are regulated more by moral feeling than by reasoning.... All their mistakes are in the direction of doing things excessively and vehemently. They overdo everything; they love too much, hate too much, and the same with everything else.
We are what we repeatedly do. Excellence, then, is not an act, but a habit.
If there is some end of the things we do, which we desire for its own sake, clearly this must be the good. Will not knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what we should? If so, we must try, in outline at least, to determine what it is.
For the things we have to learn before we can do, we learn by doing.
Those who assert that the mathematical sciences say nothing of the beautiful or the good are in error. For these sciences say and prove a great deal about them; if they do not expressly mention them, but prove attributes which are their results or definitions, it is not true that they tell us nothing about them. The chief forms of beauty are order and symmetry and definiteness, which the mathematical sciences demonstrate in a special degree.
Without friends no one would choose to live, though he had all other goods.
That judges of important causes should hold office for life is a disputable thing, for the mind grows old as well as the body.
It is simplicity that makes the uneducated more effective than the educated when addressing popular audiences.