  I review the problem of the choice of the priors from the point of view of a
physicist interested in measuring a physical quantity, and I try to show that
the reference priors often recommended for the purpose (Jeffreys priors) do not
fit to the problem. Although it may seem surprising, it is easier for an
``experienced physicist'' to accept subjective priors, or even purely
subjective elicitation of probabilities, without explicit use of the Bayes'
theorem. The problem of the use of reference priors is set in the more general
context of ``Bayesian dogmatism'', which could really harm Bayesianism.
