Kantian meditation

The holding 
        of a thing 
               to be true is 
a phenomenon
          in our understanding 
which may rest on 
             objective grounds,

but requires, also, 
                subjective causes 
in the mind of the person 
                       judging. 

If a judgement is valid 
                    for every 
                           rational being, 
then its ground 
               is objectively sufficient, 
and it is termed 
                      a conviction. 

If, on the other hand, 
                   it has its ground in 
the particular character 
                     of the subject, 
     it is termed 
                      a persuasion.

Persuasion is a mere 
                         illusion, 
the ground of 
            the judgement, 
                   which lies solely 
in the subject, 
          being regarded 
                      as objective. 

Hence a judgement 
            of this kind 
            has only private validity — 
is only valid for 
           the individual 
                     who judges,

and the holding of 
              a thing to be true 
in this way 
            cannot be 
                     communicated.

-- Immanuel Kant, The Critique of Pure Reason.