philosophical discoveries: but cannot overcome a certain shame-facedness I
have to appear among you at my years without having got a settlement, or so
much as attempted any. How happens it, that we philosophers cannot as
heartily despise the world as it despises us? I think in my conscience the
contempt were as well founded on our side as on the other." With this letter
Mr Hume transmitted to his friend a manuscript of his Essay on Miracles, a
work which he at that period declined publishing along with his other productions, looking on it as more likely to give offence, from the greater reference of its reasonings to revealed religion.
Towards the termination of the year 1738, Hume published his "Treatise of Human Nature; being an attempt to introduce the experimental method of reasoning into moral subjects." The fundamental principles on which the whole philosophy of this work is reared, discover themselves on reading the first page, in the division of all perceptions in other words, of all the materials of knowledge which come within the comprehension of the human mind, into impressions and ideas. Differing from almost all men who, using other terms, had discussed the same subject, he considered these two methods of acquiring knowledge, to differ, not in quality, but merely in degree; because by an observation of the qualities of the mind, on the principle of granting nothing which could not be demonstrated, he could find no real ground of distinction, excepting that the one set of perceptions was always of a more vivid description than the other. The existence of impressions he looked on as prior in the mind to the existence of ideas, the latter being merely dependent on, or reflected from the former, which were the first inlets of all knowledge. Among perceptions he considered the various methods by which the senses make the mind acquainted with the external world, and along with these, by a classification which might have admitted a better arrangement, he ranked the passions, which he had afterwards to divide into those which were the direct consequents of the operations of the senses, as pain and pleasure, and those which the repetition of impressions, or some other means, had converted into concomitants, or qualifications of the mind, as hatred, joy, pride, &c. By ideas, Mr Hume understood those arrangements of the perceptions formed in the mind by reasonings or imagination; and although he has maintained the distinction between these and the impressions of the senses to be merely in degree, all that has been either blamed or praised in his philosophy is foanded on the use he makes of this distinction. He has been accused, and not without justice, of confusion in his general arrangement, and disconnexion in the subjects he has discussed as allied to each other ; but a careful peruser of his works will find the division of subject we have just attempted to explain, to pervade the Avhole of his extraordinary investigations, and never to be departed from, where language allows him to adhere to it. The ideas, or more faint perceptions, are made by the author to be completely dependent on the impressions, showing that there can be no given idea at any time in the mind, to which there has not been a corresponding impression conveyed through the organs of sense. These ideas once existing in the mind, are subjected to the operation of the memory, and form the substance of our thoughts, and a portion of the motives of our actions. Thus, at any given moment, there are in the mind two distinct sources of knowledge, (or of what is generally called knowledge,) the impressions which the mind is receiving from surrounding objects through the senses, and the thoughts, which pass through the mind, modified and arranged from such impressions, previously experienced and stored up. Locke, in his arguments against the existence of innate ideas, and Dr Berkeley, when he tried to show that the mind could contain no abstract ideas, (or ideas
