Aristotle

Alexandra Ford

Aristotle was a Greek philosopher and scientist born 384 BC in the northern Greek kingdom of Macedonia. His writings on philosophy are widely studied today and included subjects such as aesthetics, ethics, government, metaphysics, politics, economics, psychology, rhetoric, and theology. While his most notable contributions were made in the area of philosophy, he is also well-known for his contributions to the study of physical sciences, including physics, biology, and zoology.

Life and Education

Aristotle was born 384 BC in the city of Stagira in northern Greece. He became a student at Plato's Academy at the age of 18 and remained there until the age of 37. Following the death of Plato, Aristotle left academy and traveled to the island of Lesbos in order to study the botany and zoology of the area. He married Pythias and had a daughter. In 343 BC Aristotle was appointed by Phillip II of Macedon to be the head of the royal academy of Macedonia. During this time he tutored Alexander the Great as well as future kings, Ptolemy and Cassander. Aristotle returned to Athens by 335 BC where he established his own school known as Lyceum. During this time he was able to produce hundreds of books and establish a library in the Lyceum. Only a small number of his works have survived to modern day. In 322 BC Aristotle died of natural causes in Euboea.

Scientific Contributions

Aristotle defined "natural philosophy" as a branch of philosophy examining the phenomena of the natural world. This natural philosophy included natural sciences such as physics and biology. More specifically, his study of theoretical science included physics, mathematics, and metaphysics. Aristotle's scientific writings were primarily qualitative and contained very little quantitative data. Because of this, much of his scientific work was eventually proved inaccurate many centuries later by scientists such as Galileo. Despite this, Aristotle's writings were still highly respected by the scientific community for many centuries following his lifetime.

Five Elements

In addition to the four elements proposed by Empedocles, Aristotle proposed a fifth element, aether.

1. Earth: cold and dry substances; corresponds to the modern idea of a solid.
2. Water: cold and wet substances; corresponds to the modern idea of liquid.
3. Air: hot and wet substances; corresponds to the modern idea of gas.
4. Fire: hot and dry substances; corresponds to the modern ideas of plasma and heat.
5. Aether: a devine substance; makes up the heavenly spheres (stars) and heavenly bodies (planets).

According to Aristotle, each of the four earthly elements has its natural place to which it tends. He proposed that these earthly elements tend toward the center of the universe which he believed to be the center of the Earth. This aligns with the geocentric thought of scholars during that time period. Aristotle also proposed that the stars and planets moved in perfect circles.

Motion

According to Aristotle, motion is "the actuality of a potentiality as such," or in other words, it is the active fulfillment of potential. Aristotle proposed the idea that the speed of a falling object is proportional to the weight of the object, and thus, heavier objects fall faster. Aristotle also proposed that the speed of a falling object in inversely proportional to the medium through which it is falling.

Causality

Aristotle proposed four causal factors to explain the coming about of anything in the universe.

1. Material cause: describes the material of which something is made.
2. Formal cause: the arrangement or form of something.
3. Efficient cause: the primary source from which the change occurs.
4. Final Cause: the purpose or function of which something is meant to serve.

Optics

In his writing Problemata, Aristotle documented his use of a camera obscura, a device analogous to the diaphragm of a modern day camera. He used the device to observe the sun as its light passed through the device. He also observed how the magnification of an image occurred as the camera obscura was moved further from the object. His writing is the second oldest account of such a device, and his theories on optics were more accurate than other philosophers of his time.

See also

• Sir Isaac Newton
• Galileo Galilei

Further reading

Physics, Aristotle

External links

http://jcmooreonline.com/2010/12/28/aristotles-enduring-contribution-to-science-education-and-physics/ http://www.britannica.com/biography/Aristotle

References

http://www.famousscientists.org/aristotle/ http://www.mlahanas.de/Greeks/AristotlePhysics.htm http://galileoandeinstein.physics.virginia.edu/lectures/aristot2.html