FIRST PROPOSITION.
The testimony of consciousness extends to all the phenomena that are realized in our soul, regarded as an intellectual and sensitive being.
SECOND PROPOSITION.
236. If there exist in our soul phenomena of a different order, that is to say, if it may in some sense be modified in non-representative faculties, the testimony of consciousness does not extend to such phenomena.
We do not advance this proposition without a solid reason. It is probable, and even very probable, that our soul has active faculties, of the exercise of which it is not conscious; otherwise how explain the mysteries of organic life? The soul is united to the body, and is for it the vital principle, the separation from which causes death, manifested in complete disorganization and decomposition. This activity is exercised without consciousness, either of the mode or of the fact of its existence.
It may be said that there is here a series of those confused perceptions of which Leibnitz speaks in his Monadologie; or that these perceptions are so slight, so wan, as to leave no trace in the memory, nor be an object of reflection: but these are only conjectures. It is hard to persuade one's self that the fœtus in the mother's womb has any consciousness of the activity exercised for the development of its organization: it is also hard to persuade one's self that even in adults there is any consciousness of that same activity producing circulation of the blood, nutrition, and other phenomena which constitute life. If these phenomena are produced, as they certainly are, by the soul, there is in it, an exercise of activity of which it either has no consciousness, or one so weak and confused that it is as if it were not.
THIRD PROPOSITION.
237. The testimony of consciousness, in itself considered, is so limited to the purely internal, that it is of itself worth nothing in the external order, either for the criterion of evidence or that of the senses.
FOURTH PROPOSITION.
The testimony of consciousness is the foundation of the other criteria, inasmuch as it is a fact which they all require, and without which they are impossible.