But the truth is that those who, swayed by doubt, begin to ask about the future consequences of virtue and vice, or about the strength and weakness of men, can never arrive at certainty. For it is seen that the very thing which is the cause of a man's success in his purpose also becomes the cause of his ruin. Human actions are therefore uncertain in their outcome. Learned men, capable of judging the wrongness of deeds, declare a certain course of action worthy to be followed; yet it leads to consequences directly opposite to those foreseen, much like the shifting of the wind. Indeed, even those human actions that result from deliberation and well-directed policy, and that accord with considerations of propriety, are thwarted by the workings of Providence.