Pantanjali's method of meditation provides an approach to illumination about the essential nature of phenomena of interest. This is the method of the ancients. Now, as then, the results of illumination need to be checked against the body of reliable knowledge about the world. Illumination, as a form of knowledge, is not, strictly speaking, truth functional. Propositions about illumination are truth functional, but not illumination.
Illumination positions self and awareness and yields equanimity.
For the practitioner, illuminations which arises through meditation provide a conviction that nature and existence are open to personal knowledge and comprehension. Mystery and Knowledge Existence is bracketed by mystery. Viewed from the perspective of the conditional nature of causality, truth functional knowledge is, at best, transient. Knowledge of ignorance is far more secure. Illumination seems to provide the only secure source of knowledge, but illumination is not truth functional.