‘Tantum religio potuit suadere malorum.’
Note that the invocation to Venus at the beginning of the poem is not inconsistent, but is an address to the universal principle of generation; cf. i. 21,
‘Quae quoniam rerum naturam sola gubernas.’
The scope of the Books is as follows: Books i. and ii. state the physical theories of Democritus and Epicurus. Book i. states the Atomic Theory of Democritus, held by Epicurus, that the world consists of atoms and void. The theories of Heraclitus, Empedocles, Anaxagoras, etc. are refuted; i. 740,
‘Principiis tamen in rerum fecere ruinas
et graviter magni magno cecidere ibi casu.’
Book ii. treats of the combinations of atoms, and the principle of the swerve introduced to explain free-will. The varieties of atoms are shown to be limited. In Book iii. the nature of the mind and life is shown to be material. Religio and the fear of death (cf. ll. 978 sqq.) are attacked principally in this Book; iii. 830,
‘Nil igitur mors est ad nos neque pertinet hilum,
quandoquidem natura animi mortalis habetur.’
Book iv. treats of the theory of simulacra or images, of the senses, and particularly of love. Book v. treats of the formation of the earth and the heavenly bodies, the origin of life, and the progress of civilization. It is shown that nothing has been created, and that everything must perish. Book vi. treats of abnormal phenomena, such as thunder and lightning, tempests, volcanoes, earthquakes, etc. The plague at Athens is described (from Thucydides). Books v. and vi. are unfinished.
Ethical views are given only by the way, the poem being primarily on physics. Pleasure is the end of action: ii. 172, ‘dux vitae dia voluptas.’ This pleasure is the absence of disturbance (ἀταραξία), hence all passion (as of love, iv. 1121-40) is deprecated; ii. 14,
‘O miseras hominum mentes, o pectora caeca!
qualibus in tenebris vitae quantisque periclis
degitur hoc aevi quodcumque est! nonne videre
nil aliud sibi naturam latrare, nisi utqui
corpore seiunctus dolor absit, mente fruatur
iucundo sensu cura semota metuque?’