Task: Question Generation
Input (English):  To Epicurus, the unhappiness and degradation of humans arose largely from the dread which they entertained of the power of the deities, from terror of their wrath. This wrath was supposed to be displayed by the misfortunes inflicted in this life and by the everlasting tortures that were the lot of the guilty in a future state (or, where these feelings were not strongly developed, from a vague dread of gloom and misery after death). To remove these fears, and thus to establish tranquility in the heart, was the purpose of his teaching. Thus the deities, whose existence he did not deny, lived forevermore in the enjoyment of absolute peace, strangers to all the passions, desires, and fears, which agitate the human heart, totally indifferent to the world and its inhabitants, unmoved alike by their virtues and their crimes.
To prove this position he called upon the atomism of Democritus, so as to demonstrate that the material universe was formed not by a Supreme Being, but by the mixing of elemental particles that had existed from all eternity governed by certain simple laws. Lucretius' task was to clearly state and fully develop these views in an attractive form; his work was an attempt to show that everything in nature can be explained by natural laws, without the need for the intervention of divine beings.
Lucretius identifies the supernatural with the notion that the deities created our world or interfere with its operations in some way. He argues against fear of such deities by demonstrating, through observations and arguments, that the operations of the world can be accounted for in terms of natural phenomena. These phenomena are the regular, but purposeless motions and interactions of tiny atoms in empty space. Meanwhile, he argues against the fear of death by stating that death is the dissipation of a being's material mind. Lucretius uses the analogy of a vessel, stating that the physical body is the vessel that holds both the mind (mens) and spirit (anima) of a human being. Neither the mind nor spirit can survive independent of the body. Thus Lucretius states that once the vessel (the body) shatters (dies) its contents (mind and spirit) can no longer exist. So, as a simple ceasing-to-be, death can be neither good nor bad for this being. Being completely devoid of sensation and thought, a dead person cannot miss being alive. According to Lucretius, fear of death is a projection of terrors experienced in life, of pain that only a living (intact) mind can feel. Lucretius also puts forward the 'symmetry argument' against the fear of death. In it, he says that people who fear the prospect of eternal non-existence after death should think back to the eternity of non-existence before their birth, which probably did not cause them much suffering.
Output (English): Of what analogy does Lucretius use for mind and spirit?