“ A man abandons himself to a fine frenzy, and the power which flows through him, as I once explained to you, makes him the medium of a great poem or a great picture. The creative action is not voluntary at all, but automatic; we can only put the mind into the proper attitude, and wait for the wind, that blows where it listeth, to breathe over it. ”
 Oliver Wendell Holmes Sr., The Autocrat of the Breakfast-Table (1858). copy citation

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“I trust the tariff of Heaven has an ad valorem scale for them—and all of us. But to come back to poets and artists;—if they really are more prone to the abuse of stimulants,—and I fear that this is true,—the reason of it is only too clear. A man abandons himself to a fine frenzy, and the power which flows through him, as I once explained to you, makes him the medium of a great poem or a great picture. The creative action is not voluntary at all, but automatic; we can only put the mind into the proper attitude, and wait for the wind, that blows where it listeth, to breathe over it. Thus the true state of creative genius is allied to reverie, or dreaming. If mind and body were both healthy and had food enough and fair play, I doubt whether any men would be more temperate than the imaginative classes.” source