I.17 - vitarka-vicāra-ānanda-asmitā-rūpa-anugamāt-saṁprajñātaḥ

The [object] is gradually understood in totality and follows [a sequence of levels]. In the beginning, there is only a superficial understanding. In time, this becomes deeper and more subtle. Then it becomes a source of pure joy. Later, the knowledge becomes into the nature of the observer. 

Such a level of perception of the nature of the object is only possible in the state of Yoga. Frequently we are able to understand the superficial and more obvious elements. But comprehension is incomplete until we have achieved perception at the deepest level without any errors