1: Aristotle believed that "linguistic assertion" (language) expresses one's belief (thought), which represents the world (reality) as it is or is not. For example, if someone believes that an object is a pen, then his belief represents the world. In order to express this belief, he uses "linguistic assertion"( i.e saying or writing it).
2: Most of Aristotle's lasting findings in science involve biology. Many of his observations on marine life are accurate to this day. His description of the arm of an octopus was 2000 years ahead of it's time, and his descriptions of catfish and angler fish were very well detailed
3: In addition to studying anatomy, Aristotle also introduced many theories and concepts in the field of biology. One of these is the concept of epigenesis: the idea that on an embryo, more generalized structures develop before more specialized ones. This theory is now generally accepted as true
4: Aristotle performed a good amount of work in physics. Many of his theories were widely believed for thousands of years. One was his belief that the rate that objects fall is proportionate to its mass. This was later proven false by Galileo.
5: Aristotle supported the early belief that the Earth was made of four elements: earth, fire, water, and air. However, Aristotle also proposed a fifth element, known as aether. Aether, according to Aristotle, constituted the stars and planets
6: One of Aristotle's most famous theories was that of a geocentric universe. He believed that the Earth sat in the center of the solar system, while the other planets and the sun revolved around it.
7: Another, more accurate, astronomical belief of Aristotle's regarded the Milky Way. A man named Democritus had claimed that the Milky Way was made up of stars shielded by the Earth from the Sun's rays. Aristotle refuted this claim, stating that the Sun is larger than the Earth and the stars in the Milky way were much further away from Earth. Therefore, the Sun shined on all of the stars, while the Earth shielded none of them.
8: Aristotle devised the Four Causes as a way to explain why something comes about. These four causes are the Material Cause (what something is made of), Formal Cause(plan before existence), Efficient Cause(what set something into motion), and Final Cause (the purpose of something).
9: Aristotle is credited as the first person to study formal logic; his findings were the dominant form of logic in Europe until the 19th century. One aspect of logic he is famous for developing is syllogism, which takes two conditional statements and forms a conclusion using the hypothesis of one statement and the conclusion of the other.
11: For almost 2000 years, Aristotle's findings were widely accepted as true. However, some of his findings have not stood the test of time, and have been proven false. For example, Aristotle believed that the rate of which an object falls is proportional to its weight. Tests by Gallileo and an expedition on the moon proved him wrong. Aristotle's views on the truth have been replaced as well. He believed that to assert the beliefs that represent the world, one must simply speak them or write them. Today, assertion comes from hard evidence and proof. However, it is impossible to deny Aristotle's influence over Europe. In fact, his influence was so great, that there was much resistance against anything contradicting Aristotle's writings.