Four diagnostic questions
1. Is the legal act, including its subject matter, capable of becoming an operative cause? If not, constitution is blocked.
2. Have the elements and legally required duration been completed? If not, completion is blocked.
3. Is a recognized right or condition preventing the initial legal effect even though its basis has arisen? This is the issue of blocked commencement.
4. Did the ruling previously arise and only later become subject to termination or rescission? This concerns continuation.
Keep noncompletion of the cause separate from subsequent cessation of a ruling. Where specification of the cause is disputed, explain why jurists may use either a fourfold or threefold classification.