Definition of "irrationalism"

Finally, with good reason, this psychology aims to be a psychology of a purely empiriological type. It is pervaded and overwhelmed on every side, however, by a pseudometaphysics of the most vulgar character, which Freud is all the less anxious to dispense iwth as he imagines he has no philosophy or metaphysics at all. I say pseudometaphysics of the most vulgar type, because it combines all the prejudices of deterministic, mechanistic scientism with all the prejudices of irrationalism.

1964, Cross Currents of Psychiatry and Catholic Morality, page 351