- Marcus Tullius Cicero (106–43 BCE) is best known to posterity as a prominent statesman and orator in the tumultuous period of the late Roman republic. As well as being a leading political actor of his time, he also wrote voluminously. Among his writings, around a dozen philosophical works have come down to us. Philosophy was a lifelong passion for Cicero. In addition to what one might call his strictly philosophical compositions, much else of what he wrote – including his speeches, works on rhetoric, and a large collection of letters – show evidence of his philosophical interests. In terms of modern scholarship, the value of Cicero’s philosophical work was held, until relatively recently, to lie chiefly in the information it provided about the thought of the leading philosophical schools of his day: Stoicism, Epicureanism and Academic scepticism among them. However, in part because of the creative way in which he engages with his predecessors, he is increasingly studied today as a philosophical thinker of independent interest.
- Square (Wikipedia)
In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length adjacent sides. It is the only regular polygon whose internal angle, central angle, and external angle are all equal (90°), and whose diagonals are all equal in length. A square with vertices ABCD would be denoted ◻ ABCD.
stanford encyclopedia of philosophy of