[30] A perplexity which is increased rather than diminished by some passages in a letter to Gilbert Elliot of Minto (March 10, 1751). Hume says, "You would perceive by the sample I have given you that I make Cleanthes the hero of the dialogue; whatever you can think of, to strengthen that side of the argument, will be most acceptable to me. Any propensity you imagine I have to the other side crept in upon me against my will; and 'tis not long ago that I burned an old manuscript book, wrote before I was twenty, which contained, page after page, the gradual progress of my thoughts on this head. It began with an anxious scent after arguments to confirm the common opinion; doubts stole in, dissipated, returned; were again dissipated, returned again; and it was a perpetual struggle of a restless imagination against inclination--perhaps against reason.... I could wish Cleanthes' argument could be so analysed as to be rendered quite formal and regular. The propensity of the mind towards it--unless that propensity were as strong and universal as that to believe in our senses and experience--will still, I am afraid, be esteemed a suspicious foundation. 'Tis here I wish for your assistance. We must endeavour to prove that this propensity is somewhat different from our inclination to find our own figures in the clouds, our faces in the moon, our passions and sentiments even in inanimate matter. Such an inclination may and ought to be controlled, and can never be a legitimate ground of assent." (Burton, _Life_, I. pp. 331-3.) The picture of Hume here drawn unconsciously by his own hand, is unlike enough to the popular conception of him as a careless sceptic loving doubt for doubt's sake. [31] Kant employs substantially the same argument:--"Wuerde das hoechste Wesen in dieser Kette der Bedingungen stehen, so wuerde es selbst ein Glied der Reihe derselben sein, und eben so wie die niederen Glieder, denen es vorgesetzt ist, noch fernere Untersuchungen wegen seines noch hoeheren Grundes erfahren."--_Kritik._ Ed. Hartenstein, p. 422. [32] _I.e._ Natural philosophers. [33] Hume's letter to Mure of Caldwell, containing a criticism of Leechman's sermon (Burton, I. p. 163), bears strongly on this point. [34] Burns published the _Holy Fair_ only ten years after Hume's death. CHAPTER IX. THE SOUL: THE DOCTRINE OF IMMORTALITY. Descartes taught that an absolute difference of kind separates matter, as that which possesses extension, from spirit, as that which thinks. They not only have no character in common, but it is inconceivable that they should have any. On the assumption, that the attributes of the two were wholly different, it appeared to be a necessary consequence that the hypothetical causes of these attributes--their respective substances--must be totally different. Notably, in the matter of divisibility, since that which has no extension cannot be divisible, it seemed that the _chose pensante_, the soul, must be an indivisible entity.