DESCARTES TO BERKELEY predict the actual course of the universe the laws must fulWl two conditions: they must be simple laws and they must be general laws This is the theme of Malebranche’s Treatise on Nature and Grace: God, discovering in the inWnite treasures of his wisdom an inWnity of possible worlds (as the necessary consequences of the laws of motion which he can establish) determines himself to create that world which could have been produced and preserved by the simplest laws, and which ought to be the most perfect, with respect to the simplicity of the ways necessary to its production or to its conservation (TNG, 116) Two simple laws of motion, according to Malebranche, suYce to explain all physical phenomena—the Wrst, that bodies in motion tend to continue their motion in a straight line; the second, that when two bodies collide, their motion is distributed in both in proportion to their size Malebranche’s belief in the simplicity and generality of fundamental laws not only solves the epistemological problem about our knowledge of the external world, but also the moral problem of the presence of evil among the creatures of a good God God could have made a world more perfect than ours; he might have made it such that rain, which makes the earth fruitful, fell more regularly on cultivated ground than on the sea, where it serves no purpose But to that he would have had to alter the simplicity of the laws Moreover, once God has established laws it is beneath his dignity to tinker with them; laws must be general not only for all places but for all times: If rain falls on certain lands, and if the sun roasts others; if weather favourable for crops is followed by hail that destroys them; if a child comes into the world with a malformed and useless head growing from his breast, it is not that God has willed these things by particular wills; it is because he has established laws for the communication of motion, of which these eVects are necessary consequences (TNG, 118) It is not that God loves monsters or devises the laws of nature to engender them: it is simply that he was not able, by equally simple laws, to make a more perfect world The key to the problem of evil is to realize that God acts by general laws and not by particular volitions Once again, we have ideas that were later summarized in Pope’s Essay on Man We are tempted, Pope says, to see nature as designed for our individual beneWt But here we meet an objection, and receive an answer: 60