Titus Lucretius Carus’ only known work is the philosophical poem De Rerum Natura, or On the Nature of Things. De Rerum Natura is one of the most important works of early Roman literature and is significant for its role in introducing Greek philosophical ideas into Latin. The work also had a significant influence on Virgil and other later poets.
Almost nothing is known about the life of Lucretius. Certainly Lucretius lived through some of the most tumultuous years of the Roman Republic. I was written that he wrote his opus in lucid moments between bouts of insanity and finally killed himself leaving Cicero to edit the work, that according to Fourth Century Christina writer St. Jerome. However there is no evidence of this is it can be surmised that Jerome’s version on events might have been influenced by the Church’s distain for Lucretius’ ideas. There is considerable evidence, however, that Lucretius died aged just 44 in 55 BCE.
The main purpose of the poem was to free men's minds of superstition and the fear of death. Lucretius describes the philosophical system of Epicurus, a third century BCE Greek who taught that pleasure and pain are the measures of what is good and bad, that death is the end of existence and not to be feared, and that gods do not reward or punish humans. Lucretius expounds upon this philosophy and calls the concept that the gods created our world or interfere with its operations mere superstition. He explains that fear of the gods can be banished by showing that the operations of the world can be accounted for in scientific terms. He explains that the motions of the world can be attributed to the regular but purposeless motions of invisible atoms and masses of atoms and not the physical intervention of gods. As a result Lucretius has sometimes been called an Atomist.
Lucretius also states that the fear of death can be overcome by understanding that death is merely the vanishing of a being's material mind, and as such, death is neither good nor bad for this being. Our dread of death is a projection of the fears we experience in life, says Lucretius, and fear of pain that only a living mind can feel. Lucretius also puts forward the 'symmetry argument' against the fear of death. Lucretius makes the argument that people fear the prospect of eternal non-existence after death but do not think upon or worry about eternity of non-existence before their birth.
Perhaps the most remarkable thing about On the Nature of Things is the fact that complex issues were dealt with in hexameter poetry. Even when discussing the motion of atoms the poetry is striking. Although history has largely demoted Lucretius from philosopher and scientist to poet, many of the ideas contained within the poem are considered orthodox science today. Certainly the science is limited and many of the concepts are disproved today, but Lucretius’ attempt to free humans from superstition and replace religion with scientific truths is considered a milestone in human understanding.

On the Nature of Things

The poem is divided into six books. The first three books describe the concepts of being and nothingness, matter and space, atoms and their movement, the infinity of the universe both in time and space, and the nature of thought and spirit, consciousness and the nature of mortality. The second part of the book explains the natural phenomena such as vision and the senses, sex and reproduction, natural forces and agriculture, the heavens, and disease.
Throughout the poem there are four essential truths explained: Substance is eternal; atoms move in an infinite void and the universe is composed only of atoms and void; the soul consists of minute atoms that dissipate when a person dies; and that while Gods exist, they did not start the universe and they have impact upon the affairs of man.  
Lucretius writes that men comprehend their world by either the senses or by reason
But while senses are dependable, reason infers underlying explanations, and reason can reach false inferences. He argues that conclusions must be continually verified against the senses. This is in contrast to Plato, who believed that senses could be fooled and reason was reliable.