'Knowledge has three degrees: opinion, science, illumination. The means or instrument of the first is sense; of the second dialectic; of the third, intuition.' - Plotinus (in Letter to Flaccus)
This threefold distinction of knowledge is consistent with the critical distinction between knowledge and belief, wherein knowledge is revealed and belief is constructed.
Similarly, knowledge gained through the senses as well as knowledge gained through reason is constructed. In contrast, knowledge gained through intuition is revealed or illuminated.