The following appears to be the true explanation: that though God foreknew all this suffering when He created the world, and in this sense _designed_ it, He need not have _desired_ it, but may have desired something else, for the attainment of which, this suffering was a necessary condition. And this _something else_ must obviously have been the training and perfecting of man's character; for which, some kind of suffering seems essential.
For if there were no suffering in the world, there could be no fortitude, no bravery, no patience, no compassion, no sympathy with others, no self-sacrifice for their good--nothing, in fact, that constitutes the highest type of man. In other words, a being such as man, can only be made perfect through suffering. Therefore this suffering implies no defect in God's design. It is a means, and, as far as we can judge, the only possible means for developing the highest and noblest character in man, such a character indeed as alone makes him worthy of admiration. Moreover, a man's character can only be formed by himself, it cannot be given him ready-made, for then it would not be _his_ character at all; and it can only be formed gradually, it cannot be done all at once. Therefore, if God wishes a man to have the special character acquired by constantly bearing suffering, it can only be obtained by constantly giving him suffering to bear.
Here, then, we have the most probable explanation of the physical evils which man endures. Their object is to develop and perfect his character; and as this is a good object, and as it cannot be obtained in any other way, they may well have been designed by a good God.
But we now come to the most difficult part of the subject, the existence of _moral evil_ in man. This, as before said, is the chief cause of human misery, and might it not have been avoided? In other words, could not all _sin_ have been excluded from the world? But assuming man to be a _free being_, it could not have been avoided, for freedom is always liable to abuse. Therefore, if God decided that man was to be free in some cases to act right or wrong, it necessarily follows that he may act wrong. No Omnipotence could possibly alter this without destroying man's freedom. Hence, though God designed all the moral evil in the world, He need not have desired it, but (as before) may have desired some totally different object, for the attainment of which, this evil was a necessary condition.