As the factors of memory and heredity together have an important bearing on the growth of moral ideas, we may deal with the subject a little more fully. According to James, "The Stream of Thought flows on: but most of its segments fall into the bottomless abyss of oblivion."[58] "Retention means _liability_ [the italics are the author's] to recall, and it means nothing more than such liability. The only proof of there being retention is that recall actually takes place."[59] His position is slightly modified some pages later, where he says, after recording a few cases of hypnotic memory: "All these pathological facts are showing us that the sphere of possible recollection may be wider than we think, and that in certain matters apparently oblivion is no proof against possible recall under other conditions." But adds: "They give no countenance, however, to the extravagant opinion that nothing we experience can be absolutely forgotten."[60] The only reason he gives, however, for discountenancing this possibility is that he cannot find sufficient explanation for it. On the other hand, we believe that there is now ample evidence to show that all experience is retained in some portion of the psychic whole, and that although it may not have been consciously realized at all, it will still have been subconsciously registered. One of the cases most often quoted in illustration of this appears in Coleridge's "Biographia Literaria"[61] and is here repeated since it is given by James and also at greater length by Hudson.[62] According to the author it occurred a year or two before his arrival at Göttingen.