I have found no better expression than "religious" for confidence in the rational nature of reality as it is accessible to human reason. Wherever this feeling is absent, science degenerates into uninspired empiricism. … I cannot accept your opinion concerning science and ethics or the determination of aims. What we call science has the sole purpose of determining what is. The determining of what ought to be is unrelated to it and cannot be accomplished methodically. Science can only arrange ethical propositions logically and furnish the means for the realization of ethical aims, but the determination of aims is beyond its scope. At least that is the way I see it.
Letter to his friend Maurice Solovine (1 January 1951) p. 120 - Einstein and Religion (1999)