To the present writer, indeed, it is conceivable that there were times when the poet's mind got the better of the most hideous of the several delusions that troubled it from time to time. The present writer can also conceive there were times when the poet, by the exercise of his will, sustained his belief in the delusion, even as the dreamer can for a few seconds by pure volition persist in believing a dream, which may be described as overlying his consciousness of its unreality. One of the prime dogmas of the school of metaphysicians, whose tenets Shelley embraced with cordial conviction of their truth, is that belief is independent of volition. The dogma is true in respect to perfectly logical and altogether sound minds. But there are unsound minds that are capable of shaping their opinions and determining their belief by processes of volition. Minds subject to manifest and distressing illusions are not to be rated as perfectly logical and altogether sound. Shelley's mind certainly was liable to such delusions. It is conceivable he would not have insisted on the separateness of belief and volition with so much needless emphasis and passion, had he not been uneasily conscious,--troubled and irritated by a criminatory sub-consciousness--that in some matters (such for instance as his delusion respecting his father) he believed what he ought not to believe, and could by strenuous volition save himself from believing. Some such thought as this was perhaps in Peacock's mind, when he spoke of the 'semi-delusions' of the man whom he loved so heartily. Returning to Eton after recovering from the fever, of which so much has been said in foregoing pages of this chapter, Shelley, to the end of his time at the public school, continued to be in most respects the same boy he was on rising to the office of Lord High Atheist. Persisting in contumacy and unruliness he left the school in disgrace, though not under any ignominy to preclude him from the advantages of further education at one of the universities. In one particular, however, he seems to have changed his course towards the close of his Etonian career. The passion for scientific amusements (let them not be called 'studies') having in some degree spent itself, he devoted the greater part of his leisure to literary exercise, in the hope of winning premature distinction as a man of letters,--an ambition he certainly would not have entertained, had he been so seriously set on scientific inquiry, and occupied with scientific interests, as successive biographers have represented.