Any idea can be brought into the classroom if the point is to inquire into its structure, history, influence and so forth. But no idea belongs in the classroom if the point of introducing it is to recruit your students for the political agenda it may be thought to imply.
A powerful attraction exists, therefore, to the promotion of a study and of duties of all others engrossing the time most completely, and which is less benefited than most others by any acquaintance with science.