It is not a "philosophy".

This terminology was common among the theologians of the time to mean "that which a thing is" and is not tied in any way to Aristotle, who spoke Greek rather than Latin.

So, it means "that which a thing is" was bread and wine, but is now Body and Blood. The "trans" references the change, the "substantio" that which the thing is.

Normally the appearance of something points to what it is, but in this case the appearances remain the same.

From the standpoint of the Church numerous other terminologies used in other communions are completely interchangeable.