At the most basic level of subconscious thought, every living animal possesses the desire to stay alive. This instinct usually remains dormant, although in dire situations we may be led to do unexpected things. In addition to this subconscious drive, there is a socially constructed motivation to fear death. Thanks to the pervasive nature of religion throughout history, much of humanity has, at one time or another, feared the prospect of eternal damnation and torture during their afterlife. While not all religions have a negative afterlife, or even a semblance of an afterlife, those religions that contain some such construct receive much more attention in this regard. Throughout history, many academics have countered people's irrational fear of the unknown by noting that there is no definitive evidence to prove the existence of such a post-mortem experience. According to Lucretius, this fundamental fear of death is entirely speculative and entirely illogical; argues that we have no reason to fear death because there is nothing after death. What makes Lucretius' argument so significant is not how he opposes religion, but how he bases it on his own revision of atomism. It is because of this foundation of logical thinking that Lucretius' writings on the nature of death can still be considered a valid hypothesis. While atomism certainly was not a new philosophy at the time Lucretius wrote, or even at the time of Rome's ascension to power, the original propositions about the nature of matter were not sufficient to construct a philosophy similar to that presented by Lucretius. Over time, atomism evolved from a binary view that the world consisted solely of atoms and void,… at the center of the paper… physically present. While this seems daunting, it shouldn't be uncomfortable; it is simply a reminder of the fleeting nature of life and the fact that no one can avoid death. In addition to describing how and why the soul leaves a body at death, Lucretius argues that the soul only arrives and attaches itself to the body at birth. While this seems like somewhat roundabout logic out of context, it is simply a condensed conclusion to his previous argument. The basis of this part of his argument comes, once again, from the central principle of atomism. Since nothing is created or destroyed, the atoms that make up the soul must exist before birth, even if the union of the two occurs only when one enters the world. Only by understanding the ephemeral nature of both soul and body, says Lucretius, can we come to accept the inevitable.