As presently defined?
What was solemnly pronounced, declared and defined a certain point of time is not an indication that it only came to be believed at that point.
It has been the “constant teaching” in our house that when the kids come home from school they are to do certain things: hang up their backpacks, put their shoes away, wash their hands, take off their uniforms, eat their snack, finish their chores, practice their piano, etc etc etc.
Despite the fact that they have been doing this every school day for 2-11 years every once in a while we need to have a “family meeting” to pronounce, declare and define exactly who should be doing which job and how it is to be done. (Note: I try to ignore their incredulous looks that say, “What? We’re supposed to hang up our backpacks again this year?” or “What? You’ve never said that we had to take off our uniforms and hang them up!” )
At this council we recall what’s been done in the past, review the current norms and define again exactly what’s the expectation. Sometimes the kids complain that we are “making up new rules”, claiming we’ve “never done it this way before” when in actuality we are just pronouncing, declaring and defining a standard norm of our family.
Thus, the solemn declaration of the dogma of the Immaculate Conception was not newly formed in 1854. It was a constant belief held and spoken of for many years, sometimes correctly, sometimes incorrectly. Perhaps in order to alleviate any doubt and to correct any wrong information, God chose 1854 as the time to pronounce, declare and define this belief and practice.
However, this dogma was ancient, dating back to before St. Thomas Aquinas.