Perhaps there is no other knowing than the mere competence of the act. If at the heart of one's being, there is no self to which one ought to be true, then sincerity is simply nerve; it lies in the unabashed vigor of the pretense. But pretense is only pretense when it is assumed that the act is not true to the agent. Find the agent.
If I have renounced the search of truth, if I have come into the port of some pretending dogmatism, some new church, some Schelling or Cousin, I have died to all use of these new events that are born out of prolific time into multitude of life every hour. I am as bankrupt to whom brilliant opportunities offer in vain. He has just foreclosed his freedom, tied his hands, locked himself up and given the key to another to keep.
For the great majority of mankind are satisfied with appearances, as though they were realities, and are often more influenced by the things that seem than by those that are.
I have not professionally dealt in truth. Many when they come to die have spent all the truth that was in them, and enter the next world as paupers. I have saved up enough to make an astonishment there.
Nor seek, for this is also sooth,
To hunger fiercely after truth,
Lest all thy toiling only breeds
New dreams, new dreams; there is no truth
Saving in thine own heart.