If we turn to the reasoning faculties we find that they have been the cause of most contention and misunderstanding. On the one hand have been the extreme intuitionalists, or deductive theorizers, who for centuries limited philosophical thought almost entirely to fruitless, abstract, deductive reasoning based upon premises that had no real foundation in facts. As John Stuart Mill pointed out, the mind may become so accustomed to conceiving of a thing as true that it seems like an axiomatic truth, although facts discovered later may show that it was an error. Thus the time was before modern discoveries, when people could not conceive of persons living under the earth walking with their heads down, or of objects attracted towards each other without some material object to connect them and thus draw them together. Other extremists have looked upon the mind as a blank sheet, or have become so skeptical of its intuitive impressions that they mistrust its guidance almost entirely, especially in religious matters; although, strange to say, they inconsistently seem to trust it all the more in material things. It cannot be denied that our "think so's," "feel so's," impressions, prejudices and inherited or preconceived ideas may seem as infallible to us as any so-called axiomatic or intuitive truths. This delusion of the mind has led to multitudes of errors and has held people in bondage to ignorance and superstition in all centuries and in all countries. It has ever been the greatest hindrance to progress. Closely allied to this and reinforcing it is the inertia of the mind, through which it naturally continues to run in the grooves in which it has been running. After awhile the grooves or ruts become so deep and smooth that it seems next to impossible to turn out of them without breaking something or upsetting the mental team. We see on every hand how hard it is to get away from the ideas we have inherited or in which we have lived a long time. When truth, like a vine-dresser, has attempted to trim off these unnecessary and injurious accretions, it has always raised the hue and cry that the foundations of truth were being destroyed.