Fluidity and Transparency of Water, that it would suffocate him, or from the Light and Warmth of Fire, that it would consume him. No Object ever discovers, by the Qualities, which appear to the Senses, either the Causes, which produc'd it, or the Effects, which will arise from it; nor can our Reason, unassisted by Experience, ever draw any Inferences concerning real Existence and Matter of Fact.
This Proposition, that Causes and Effects are discoverable, not by Reason, but by Experience, will readily be admitted with regard to such Objects, as we remember, to have been once altogether unknown to us; since we must be conscious of the utter Inability we then lay under of foretelling what would arise from them. Present two smooth Pieces of Marble to a Man, who has no Tincture of natural Philosophy; and whatever Degree of Sense or Reason he may be endow'd with, he will never discover, that they will adhere together in such a Manner as to require great Force to separate them in a direct Line, while they make so small Resistance to a lateral Pressure. Such Events, as bear little Analogy to the common Course of Nature, are also readily acknowledged to be known only by Experience; nor does any Man imagine that the Explosion of Gunpowder, or the Attraction of a Loadstone could ever be discover'd by Arguments a priori. In like manner, when an Effect is suppos'dto
