Value is that which one acts to gain and/or keep – virtue is the act by which one gains and/or keeps it.
As previously mentioned, happiness is man’s ultimate value and objective. It is the one value that encompasses all of his other values. His happiness is not guaranteed though. In seeking his happiness he recognizes that a necessary prerequisite is the security and maintenance of his life. If he ceases to exist then nothing else really matters from his viewpoint.
The only exception being the fact that he may be willing to give his life if it meant saving the life of a loved one. This does not contradict the fact that his happiness is still his ultimate value as he would undoubtedly be happy to save the life of a loved one in this instance. Nevertheless, if he wishes to live it is still necessary that he must secure his sustenance.
In order to secure his sustenance he must engage in productive activity (or rely on the charitable support of others which he should do his best to avoid so as not to be a burden on others). It follows then that productive activity is an essential virtue.
In order to engage in productive activity he must use the faculty of reason and engage in the action of rational thought in order to identify and determine the best choices for bringing about his desired results. Therefore, his highest virtues are thinking and productive activity.