Greek philosopher, considered one of the founders of the theory of nuclear physicist.
The chronology of Democritus cannot be set with certainty. It is known that he lived in the V - IV BC. His life was very long and rich in travel, which would have visited Egypt, Babylon and Persia to study. He was a friend and disciple of Leucippus (founder of the first Greek atomism) and contemporary of Socrates and the doctor Hipócrates de Cos. Researcher opened the most varied interests, as the catalogue of works that has left us Diógenes Laércio attests. His writings are grouped into thirteen tetralogies which are classified under five themes: ethical, physical, mathematical, philological, and technical books. In addition, wrote works on astronomy, geography and natural sciences. Cicero praises his style both for the beauty of its language clarity, in contrast with the darkness of Heraclitus.
The historical meaning of the philosophy of Democritus is the originality of its methodological and critical aspects concerning hermeneutics. Democritus differs from the other pre-Socratic not only by the doxography, but also by using the defining and demonstrative method to "save the phenomena" back from them to "what is earlier by nature". This procedure Democritus called demonstration (kitiologi). Democritus initiates the systematic period of the history of philosophy.
Democritus explained his doctrine in the book Miakros diakosmos (the small system in the world), which we know only by indirect references. The work expresses a conception of founded nature, as of his master, in the principles of being and not being of the Eleatic tradition. Being has the traits of the pure being of Parmenides: is full, indivisible, or generated or corruptible. But unlike the one eleatico, that in addition to being single is stationary, being of Democritus is infinite in terms of the number, is a various of "atoms" countless, which differ from each other only by the way, and who are in continuous spontaneous movement. The various and movement of these atoms is due to not being, vacuum. Express opposition to the fundamental principle of eleatico thinking, ancient atomism, in order to "save the phenomena", argues that "the existence of the thing is not greater than the existence of nothing", or also "being, it is not that no one". Each atom ("indivisible") is the (non-empty), indivisible because of its strength. This corporeal indivisibility has its corresponding "indivisible form". Such forms indivisible, infinitely varied, spontaneously move in a vacuum without resistance if not, are separate, are added and infinitely varied and different, dissolved in an eternal vibration, where come from those eddies generated worlds, also compounds of atoms and vacuum. In this way, the motion of atoms in a vacuum results the birth and death of the different entities, without loss of the real elements and, at the same time, excluding any finalist conception.
Being and non-being are not detectable inventories; in the field of sensitive perception they are, on the other hand, bodies composed of atoms and void. Therefore two types of knowledge are given: the "dark", which is the one of the five senses, and the 'authentic', that of the mind or thought. Feelings and thought, soul or life in general, also are atoms scattered throughout the body, except for the atoms of the mind which are concentrated, according to Hippocrates, in the brain. The sensations are caused by the shock of external atoms with the atoms of the vegetative and sensitive soul. Thus man is in immediate relationship with "visible and tangible" bodies. Thus occurs first sensitive knowledge, which is a spurious know, mere opinion. This issue will be taken up by the Greek skepticism in the formula: "don't know nothing in authentic form, because the truth lies in the depths". Man is, therefore, away from the real thing, that is, the perception of the atoms and the void. The problem is in knowing whether man can perceive to be and not to be from this spurious knowledge and through authentic knowledge.
Ethics is exposed in the Corpus democriteum and is the most consistent part of what remains of this book. He is considered the man as a "microcosm", a set of atoms and vacuum, and his fate is the same as that of the cosmos that belongs. The end of man is the preservation of the balance, i.e., the serenity of mind"or"well-being", which is not the same that the enjoyment of the pleasures of sensitive, but that State that man is in equilibrium, without troubles by fear, or superstitious fear the gods or by any passion.
Democritus exposes a Demonology in order to explain some special phenomena, such as the vision of strange beings who come to men, including some brought goods and other ills. The problem of the divine is not a religious sense, refers to very special natural conformations "which dissolve with great difficulty, without being precisely immortal". For Democritus, therefore there are no gods. The origin of religion is in terror and astonishment of primitive men against extraordinary events, and even before the wonderful uniformity of nature. Since there are no gods, are useless pleas, because everything that men expect of them is in their own hands.