Holbach had not clearly thought out the growth, the changes, varieties, and transformations among moral ideals. He was, of course, far too much in the full current of the eighteenth century not to feel that exultation in life and its most exuberant manifestations, which the conventional moralists of the theological schools had set down and proscribed as worldliness and fleshliness. "_Action_," he says in this very chapter; "_action is the true element of the human mind_; no sooner does man cease to act, than he falls into pain and weariness of spirit." No doubt this is too absolutely stated, if we are to take some millions of orientals into our account of the human mind, but it has been true of the nations of the west. Yet the recognition of this law did not prevent the writer from occasionally falling into some of the old canting commonplaces about people being happiest who have fewest wants. As if, on the contrary, that action which he describes as the true element of man, were not directly connected with the incessant multiplication of wants. We may take this, however, as a casual lapse into the common form of moralists of ascetic ages. In substance the _System of Nature_ is essentially a protest against ascetic and quietist ideals. * * * * * The second half of the _System of Nature_ treats of the Deity; the proofs of his existence; his attributes; the manner in which he influences the happiness of men. What is remarkable is that here we have an onslaught, not merely on the Church with its overgrowth of abuses, nor on Christianity with its overgrowth of superstitions, but on that great conception which is enthroned on unseen heights far above any Church and any form of Christianity. It is theism, in its purest as in its impurest shape, that the writer condemns. No more elaborate, trenchant, and unflinching attack on the very fundamental propositions of theology, natural or revealed, is to be found in literature. Pure rationalism has nothing to add to this destructive onslaught. The tone is not truly philosophic, because the writer habitually regards the notion of a God as an abnormal and morbid excrescence, and not as a natural growth in human development. He takes no trouble, and it would have been an incredible departure from the mental fashion of the time if he had taken any trouble, to explain theology, or to penetrate behind its forms to those needs, aspirations, and qualities of human constitution in which theology had its best justification, if not its earliest source. He regards it as an enemy to be mercilessly routed, not as a force with which he has to make his account. Still, as a piece of rough and remorseless polemic, the second part of the _System of Nature_ remains full of remarkable energy and power. The most eager Nescient or Denier to be found in the ranks of the assailants of theology in our own day is timorous and moderate compared with this direct and on-pressing swordsman.