[Footnote 7.  In general we may observe, that as our assent to all probable reasonings is founded on the vivacity of ideas, It resembles many of those whimsies and prejudices, which are rejected under the opprobrious character of being the offspring of the imagination.  By this expression it appears that the word, imagination, is commonly usd in two different senses; and tho nothing be more contrary to true philosophy, than this inaccuracy, yet in the following reasonings I have often been obligd to fall into it.  When I oppose the Imagination to the memory, I mean the faculty, by which we form our fainter ideas.  When I oppose it to reason, I mean the same faculty, excluding only our demonstrative and probable reasonings.  When I oppose it to neither, it is indifferent whether it be taken in the larger or more limited sense, or at least the context will sufficiently explain the meaning.]

SECT.  X. OF THE INFLUENCE OF BELIEF.

But though education be disclaimed by philosophy, as a fallacious ground of assent to any opinion, it prevails nevertheless in the world, and is the cause why all systems are apt to be rejected at first as new and unusual.  This perhaps will be the fate of what I have here advanced concerning belief, and though the proofs I have produced appear to me perfectly conclusive, I expect not to make many proselytes to my opinion.  Men will scarce ever be persuaded, that effects of such consequence can flow from principles, which are seemingly so inconsiderable, and that the far greatest part of our reasonings with all our actions and passions, can be derived from nothing but custom and habit.  To obviate this objection, I shall here anticipate a little what would more properly fall under our consideration afterwards, when we come to treat of the passions and the sense of beauty.

There is implanted in the human mind a perception of pain and pleasure, as the chief spring and moving principle of all its actions.  But pain and pleasure have two ways of making their appearance in the mind; of which the one has effects very different from the other.  They may either appear in impression to the actual feeling, or only in idea, as at present when I mention them.  It is evident the influence of these upon our actions is far from being equal.  Impressions always actuate the soul, and that in the highest degree; but it is not every idea which has the same effect.  Nature has proceeded with caution in this came, and seems to have carefully avoided the inconveniences of two extremes.  Did impressions alone influence the will, we should every moment of our lives be subject to the greatest calamities; because, though we foresaw their approach, we should not be provided by nature with any principle of action, which might impel us to avoid them.  On the other hand, did every idea influence our actions, our condition would not be much mended.  For such is the unsteadiness and activity of thought, that the images of every thing, especially of goods and evils, are always wandering in the mind; and were it moved by every idle conception of this kind, it would never enjoy a moment’s peace and tranquillity.