The liturgy of the word and the liturgy of the Eucharist are two necessary elements in order for a church service to constitute a mass. Since Good Friday only has a liturgy of the word, it does not constitute a mass.
Now, according to Catholic theology, the mass is the very same sacrafice of Christ on Calvary. The only difference is that the former is, judging from accidental properties, unbloody whereas the latter is bloody.
Good Friday commemorates the day on which Christ sacraficed Himself for us. It would seem to me that, if there should be any day that the sacrafice of the mass is to be offered, it is Good Friday. However, I do concede that there is probably something that I don’t fully understand.
Today, Holy Thursday, we celebrated with mass the day on which Christ instituted the Eucharist. However, the institution of the Eucharist in the Last Supper is not the Sacrafice, which happens on Good Friday.
So, why do we not celebrate mass on Good Friday?
Is it simply because that the Good Friday service is written in a way that reflects the starkness of the Passion?
Is it to deflect attention away from the institution of the Eucharist (Holy Thursday), and the saving commemoration of the Sacrafice–a commemoration which only comes after the Passion?
I am very interested in hearing what people have to say!