movement, producing what the moralist values, and a destructive movement, abolishing the same. Lucretius knows very well that this distinction is moral only, or as people now say, subjective. No one else has pointed out so often and so clearly as he that nothing arises in this world not helped to life by the death of some other thing;[3] so that the destructive movement creates and the creative movement destroys. Yet from the point of view of any particular life or interest, the distinction between a creative force and a destructive force is real and all-important. To make it is not to deny the mechanical structure of nature, but only to show how this mechanical structure is fruitful morally, how the outlying parts of it are friendly or hostile to me or to you, its local and living products. This double colouring of things is supremely interesting to the philosopher; so much so that before his physical science has reached the mechanical stage, he will doubtless regard the double aspect which things present to him as a dual principle in these things themselves. So Empedocles had spoken of Love and Strife as two forces which respectively gathered and disrupted the elements, so as to carry on between them the Penelope’s labour of the world, the one perpetually weaving fresh forms of life, and the other perpetually undoing them.[4] It needed but a slight concession to traditional rhetoric in order to exchange these names, Love and Strife, which designated divine powers in Empedocles, into the names of Venus and Mars, which designated the same influences in Roman mythology. The Mars and Venus of Lucretius are not moral forces, incompatible with the mechanism of atoms; they are this mechanism itself, in so far as it now produces and now destroys life, or any precious enterprise, like this of Lucretius in composing his saving poem. Mars and Venus, linked in each other’s arms, rule the universe together; nothing arises save by the death of some other thing. Yet when what arises is happier in itself, or more congenial to us, than what is destroyed, the poet says that Venus prevails, that she woos her captive lover to suspend his unprofitable raging. At such times it is spring on earth; the storms recede (I paraphrase the opening passage),[5] the fields are covered with flowers, the sunshine floods the serene sky, and all the tribes of animals feel the mighty impulse of Venus in their hearts. The corn ripens in the plains, and even the sea bears in safety the fleets that traverse it.