Thinking that it would be interesting to read this work, I searched for a copy only to find out that Hortensius is a lost work.
My initial reaction was sadness to loose the tool that shaped the life of a great man like Augustine. The thought then struck me that the value of the creation depends less on the quality of the tool than on the skill of the craftsman. A skilled craftsman can use inferior tools to produce a good result.
Had we a copy of this work, we might find it to be inferior to other works of that period. The fact that God, in his sovereignty did not see to its preservation would seem to support this premise. Yet, it was used my God to shape a mind that has left a huge positive impact on all of Christendom.
From this I conclude that I should not mourn the loss of the tool, but praise the skill of the Craftsman who can use whatever tool is available to bring His vision into being.
The greatest virtue of the tool is availability to the Craftsman. If we are available, we get to participate in the bringing about of something beautiful.