Immorality makes us *pretend* to want truth
Just as an experiment, I’m going to try to explain “Morality is our epistemic immune system” using only premises that are self-evident:
People naturally desire to avoid pain.
Realizing that we owe someone an apology, or that we need to change our lifestyle, or that we have done harm — is painful. Therefore, people naturally desire to avoid it (#1).
Immoral behavior, which makes that painful realization necessary, makes us desire to hide the truth of our guilt, from ourselves and others.
Any desire that conflicts with truth, is a desire to not understand. (for these less self-evident ones, I’m hoping to compensate by writing about them a lot)
The desire to hide truth from ourselves (#3) conflicts with truth, and therefore is a desire to not understand (#4).
Therefore, immoral behavior creates the desire to not understand, and morality keeps us safe from the desire to not understand. (i.e., is our epistemic immune system)
Any attempt at knowledge/epistemology is futile — even nonsensical — without the desire for truth.
If we are merely pretending to want the truth, but are effectively unwilling to accept it, it’s the same as having no desire for truth at all.
Immoral behavior makes the will unable to accept truth, because it’s too painful — it makes us desire to not understand.
You can seek truth with your mind all you want, but if your will is occupied with protecting you from realizing your guilt, and desiring to not understand, it will force your mind to cooperate.
Only honest desire for truth can bear fruit, and the ability to be honest is an objective psychological capacity — not something we have simply because we declare that we have it.
Morality defends our ability to be honest, and without that ability, knowledge-seeking is vain masturbation.