The last aspect of Paticcasamuppada is the one to one correspondence between cause and effect (evam dhammata). Every cause leads only to the relevant effect; it has nothing to do with the irrelevant effect. In other words, every cause is the sufficient and necessary condition for the corresponding effect. This fact leaves no room for belief in chance or moral impotency (akiriyaditthi) but, as Visuddhimagga says, for those who misunderstand it, it provides the basis for rigid determinism (niyatavada). As for the contemplating yogi, he clearly sees the relevancy of each effect to its cause and so he has no doubt about their one to one correspondence and the reality of moral freedom.
I have dwelt at length on noteworthy facts about Paticcasamuppada. These will be clear to the yogis who consider them on the basis of their experience but as the doctrine is profound, they will not be able to grasp some facts that are beyond their intellectual level. It is of course only the omniscient Buddha who knew everything thoroughly. The yogi should make it a point to know fully as far as possible within the scope of his intellect. To this end, he should learn from the discourses of bhikkhus, reflect over what he has learnt and enrich his understanding through the practice of mindfulness.
Of the three methods of study, the third method (bhavanamaya) is the most important for the yogi who gains insight knowledge by this method, attains the holy path and is liberated from the dangers of the lower worlds.