136. Serious communications are distinguished by the gravity of the subjects of which they treat, and by the seriousness of their tone. Every communication exempt from coarseness and frivolity, and having in view a useful object, even though it be one of merely private interest, may be classed as " serious; " but, nevertheless, it may not be exempt from error. Serious spirits are not all equally enlightened ; there are many things of which they are ignorant, and concerning which they may be mistaken. For this reason, spirits who are really superior constantly advise us to submit all communications to the test of examination and of reason.
It is therefore imperatively necessary to distinguish between communications that are seriously true and communications that are seriously false. But this is not always easy ; for it is often under the guise of seriousness that presumptuous and superficial spirits seek to foist upon us their erroneous ideas and absurd theories, unscrupulously assuming the most honoured and even the most venerated names, in order the more effectually to impose upon us ; a method of deception which constitutes one of the most dangerous stumbling-blocks of practical spiritism. We shall return to this subject, of which we shall treat, farther on, with all the minuteness that its importance demands ; we shall then point out the means of guarding ourselves against false communications.