Let's now start with the beginning. All those capable of basic reasoning have at some point wondered what life is. What's the purpose of life? How do I know I am alive? These are just a few questions that seem to have swept humans for a long time. For a moment, let's move away from humans, and focus specifically on life as a general entity. Think of a frog, a bacterium, a rose, or even an extraterrestrial life form. We are going to look at the principles which govern universal life.
As chemistry lies on physics, so does biology lie on chemistry. That is, in order to understand the development of life, we must look at the development of those which make up life: chemical compounds and their behaviour. It is conclusively established that atoms seek stable electron configuration, and this is what drives atoms. The pursuit of chemical stability ultimately results in the development of life forms. By definition, all life is self-supporting (survival) and self-propagating (multiplication). The chemical and physical properties that are correct in the known Universe, say Earth, may differ elsewhere. However, regardless of properties, the Fundamental Principle applicable to atoms still remains the same (whether light or heavy, positively or negatively charged, atoms still seek the same property of stability).
The same applies for the principles of life. Whether on Earth or elsewhere, complex or simple, microscopic or giant, all life follows the principles that say life is self-supporting and self-propagating. Bearing this in mind, the following Post is about Alien Life, and how other principles of life may be a guide to predicting life on other planets.