Heraclitus was a philosopher who proposed compelling ideas; he believed that change is determined by a cosmic order through a harmonious union of opposites, such as how we are simultaneously young and old and coming into and going out of existence. Day and night, black and white, summer and winter, and yin and yang are just a few examples of what Heraclitus referred to as a harmonious union of opposites. What makes this idea interesting is that some cultures use this as a basis for spiritual guidance. Heraclitus’s idea of change brought about the problem of personal identity by acknowledging that we are not the same person today as we were yesterday; for example, the atoms of George Bush Sr. in 1959 are not the same atoms of George Bush Sr. in 2005. This intriguing idea likely led the field of psychology to address the issue of personality traits and continuity over the lifespan.
Empedocles was an interesting philosopher who maintained that the basic material particles of earth, air, fire, and water are elements that interact in different combinations to create the changing objects of experience. This idea is common and feasible considering that some of these elements are existent in all experiences; air and earth are two elements that are common to all experience in life. As I write this response I sit on the Earth breathing air while drinking a bottle of water.
Anaxagoras was a philosopher who proposed the compelling idea that the universe was an infinite and undifferentiated mass until mind acted on matter. Once this occurred, he believed that the sun, stars, moon, and air were gradually separated into the configurations of particles that we recognize in the other objects of experience; I find this idea compelling due to its similarity to the Big Bang Theory.
The atomists Leucippus and Democritus suggested that all things are composed of physical atoms that are infinitely numerous and eternally in motion according to physical laws; this idea is compelling due to the fact that it was developed around 460 – 370 B.C.E. and it is used still today. This idea led to the development of Isaac Newton’s formula of E = mc2; what goes up must come down according to the physical laws of weight and gravity.