There is an inconvenience which attends all abstruse reasoning. that it may silence, without convincing an antagonist, and requires the same intense study to make us sensible of its force, that was at first requisite for its invention. When we leave our closet, and engage in the common affairs of life, its conclusions seem to vanish, like the phantoms of the night on the appearance of the morning; and `tis difficult for us to retain even that conviction, which we had attain'd with difficulty. This is still more conspicuous in a long chain of reasoning, where we must preserve to the end the evidence of the first propositions, and where we often lose sight of ail the most receiv'd maxims, either of philosophy or common life.
Treatise 3.1.1
