NewThoughtLibrary.com / DivineLibrary.org

internal worlds, and whether either or both of them can furnish a valid proof of their being, are inquiries that are now to find settlement, or to be left unsolved doubts, unexplained fears, ultimate mysteries, drifting athwart the mind, restricting its spiritual vision, and displacing its cheerful surface-life with the shadows of deep, despairing clouds.

Yet these discussions are as subtile and perplexing as they are important; and moreover are looked on by patient plodders amid facts most influential and serviceable men as hopeless and futile. They regard these labors as the mere money-maker would regard another expedition to the North Pole. The whole region, to the purely scientific mind, seems one of chimeras, not dire only because increasing wisdom enables us to laugh at them. Ghosts are always unproductive, and to men ridiculous. The only touch of kindly sentiment that the student of natural science has on this subject, is the regret that so many are still found to waste a hope or a fear on such airy existences; are yet unwilling to confront daylight with open eyes, instead of owling in invisible regions for invisible things. In these fields of difficult and abstruse inquiry, we shall need to work our way slowly and patiently, confronting our adversaries fairly, ourselves convinced of the importance of the truths here hidden; sanguine as to the power of the mind to push and answer the questions most intimate to its own destiny, and repelling the scorn of ignorance with the silence of settled conviction; knowing that if ours or another's keel shall ever touch the distant shores of truth, shall ever add to the hemisphere of matter that of mind, the question, Who are fools? will be easily settled.

The ideas in dispute have received various designations. They have been termed innate ideas, regulative ideas, intuitive ideas, a priori ideas, categorical ideas, and also have been regarded as forms of thought, entirely independent of